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One of AMD's primary goals with Zen was an IPC increase of at least 40%, however in February 2017 AMD announced that they had actually achieved a 52% increase. Processors made on the Zen architecture are built on the 14 nm FinFET node and have a renewed focus on single-core performance and HSA compatibility. Previous processors from AMD were either built in the 32 nm process ("Bulldozer" and "Piledriver" CPUs) or the 28 nm process ("Steamroller" and "Excavator" APUs). Because of this, Zen is much more energy efficient. The Zen architecture is the first to encompass CPUs and APUs from AMD built for a single socket (Socket AM4). Also new for this architecture is the implementation of simultaneous multithreading (SMT) technology, something Intel has had for years on some of their processors with their proprietary hyper-threading implementation of SMT. This is a departure from the "Clustered MultiThreading" design introduced with the Bulldozer architecture. Zen also has support for DDR4 memory. AMD released the Zen-based high-end Ryzen 7 "Summit Ridge" series CPUs on March 2, 2017, mid-range Ryzen 5 series CPUs on April 11, 2017, and entry level Ryzen 3 series CPUs on July 27, 2017. AMD later released the Epyc line of Zen derived server processors for 1P and 2P systems. In October 2017, AMD released Zen-based APUs as Ryzen Mobile, incorporating Vega graphics cores. In January 2018 AMD has announced their new lineup plans, with Ryzen 2. AMD launched CPUs with the 12nm Zen+ microarchitecture in April 2018, following up with the 7nm Zen 2 microarchitecture in June 2019, including an update to the Epyc line with new processors using the Zen 2 microarchitecture in August 2019, and Zen 3 slated for release in Q3 2020.
As of 2019, AMD's Ryzen processors were reported to outsell Intel's consumer desktop processors. At CES 2020 AMD announced their Ryzen Mobile 4000, as the first 7 nm x86 mobile processor, the first 7 nm 8-core (also 16-thread) high-performance mobile processor, and the first 8-core (also 16-thread) processor for ultrathin laptops. This generation is still based on the Zen 2 architecture. In October 2020, AMD announced new processors based on the Zen 3 architecture. On PassMark's Single thread performance test the Ryzen 5 5600x bested all other CPUs besides the Ryzen 9 5950X. In April 2020, AMD launched three new SKUs which target commercial HPC workloads & hyperconverged infrastructure applications. The launch was based on Epyc’s 7 nm second-generation Rome platform and supported by Dell EMC, Hewlett Packard Enterprise, Lenovo, Supermicro, and Nutanix. IBM Cloud was its first public cloud partner. In August 2022, AMD announced their initial lineup of CPUs based on the new Zen 4 architecture. The Steam Deck, PlayStation 5, Xbox Series X and Series S all use chips based on the Zen 2 microarchitecture, with proprietary tweaks and different configurations in each system's implementation than AMD sells in its own commercially available APUs.
In March 2025 AMD announced Instella an open source large language model. Graphics products and GPUs. Radeon within AMD. In 2007, the ATI division of AMD released the TeraScale microarchitecture implementing a unified shader model. This design replaced the previous fixed-function hardware of previous graphics cards with multipurpose, programmable shaders. Initially released as part of the GPU for the Xbox 360, this technology would go on to be used in Radeon branded HD 2000 parts. Three generations of TeraScale would be designed and used in parts from 2007 to 2015. Combined GPU and CPU divisions. In a 2009 restructuring, AMD merged the CPU and GPU divisions to support the company's APUs, which fused both graphics and general purpose processing. In 2011, AMD released the successor to TeraScale, Graphics Core Next (GCN). This new microarchitecture emphasized GPGPU compute capability in addition to graphics processing, with a particular aim of supporting heterogeneous computing on AMD's APUs. GCN's reduced instruction set ISA allowed for significantly increased compute capability over TeraScale's very long instruction word ISA. Since GCN's introduction with the HD 7970, five generations of the GCN architecture have been produced from 2011 through at least 2018.
Radeon Technologies Group. In September 2015, AMD separated the graphics technology division of the company into an independent internal unit called the Radeon Technologies Group (RTG) headed by Raja Koduri. This gave the graphics division of AMD autonomy in product design and marketing. The RTG then went on to create and release the Polaris and Vega microarchitectures released in 2016 and 2017, respectively. In particular the Vega, or fifth-generation GCN, microarchitecture includes a number of major revisions to improve performance and compute capabilities. In November 2017, Raja Koduri left RTG and CEO and President Lisa Su took his position. In January 2018, it was reported that two industry veterans joined RTG, namely Mike Rayfield as senior vice president and general manager of RTG, and David Wang as senior vice president of engineering for RTG. In January 2020, AMD announced that its second-generation RDNA graphics architecture was in development, with the aim of competing with the Nvidia RTX graphics products for performance leadership. In October 2020, AMD announced their new RX 6000 series series GPUs, their first high-end product based on RDNA2 and capable of handling ray-tracing natively, aiming to challenge Nvidia's RTX 3000 GPUs.
Semi-custom and game console products. In 2012, AMD's then CEO Rory Read began a program to offer semi-custom designs. Rather than AMD simply designing and offering a single product, potential customers could work with AMD to design a custom chip based on AMD's intellectual property. Customers pay a non-recurring engineering fee for design and development, and a purchase price for the resulting semi-custom products. In particular, AMD noted their unique position of offering both x86 and graphics intellectual property. These semi-custom designs would have design wins as the APUs in the PlayStation 4 and Xbox One and the subsequent PlayStation 4 Pro, Xbox One S, Xbox One X, Xbox Series X/S, and PlayStation 5. Financially, these semi-custom products would represent a majority of the company's revenue in 2016. In November 2017, AMD and Intel announced that Intel would market a product combining in a single package an Intel Core CPU, a semi-custom AMD Radeon GPU, and HBM2 memory. Other hardware. AMD motherboard chipsets.
Before the launch of Athlon 64 processors in 2003, AMD designed chipsets for their processors spanning the K6 and K7 processor generations. The chipsets include the AMD-640, AMD-751, and the AMD-761 chipsets. The situation changed in 2003 with the release of Athlon 64 processors, and AMD chose not to further design its own chipsets for its desktop processors while opening the desktop platform to allow other firms to design chipsets. This was the "Open Platform Management Architecture" with ATI, VIA and SiS developing their own chipset for Athlon 64 processors and later Athlon 64 X2 and Athlon 64 FX processors, including the Quad FX platform chipset from Nvidia. The initiative went further with the release of Opteron server processors as AMD stopped the design of server chipsets in 2004 after releasing the AMD-8111 chipset, and again opened the server platform for firms to develop chipsets for Opteron processors. As of today, Nvidia and Broadcom are the sole designing firms of server chipsets for Opteron processors.
As the company completed the acquisition of ATI Technologies in 2006, the firm gained the ATI design team for chipsets which previously designed the Radeon Xpress 200 and the Radeon Xpress 3200 chipsets. AMD then renamed the chipsets for AMD processors under AMD branding (for instance, the CrossFire Xpress 3200 chipset was renamed as AMD 580X CrossFire chipset). In February 2007, AMD announced the first AMD-branded chipset since 2004 with the release of the AMD 690G chipset (previously under the development codename "RS690"), targeted at mainstream IGP computing. It was the industry's first to implement a HDMI 1.2 port on motherboards, shipping for more than a million units. While ATI had aimed at releasing an Intel IGP chipset, the plan was scrapped and the inventories of Radeon Xpress 1250 (codenamed "RS600", sold under ATI brand) was sold to two OEMs, Abit and ASRock. Although AMD stated the firm would still produce Intel chipsets, Intel had not granted the license of FSB to ATI. On November 15, 2007, AMD announced a new chipset series portfolio, the AMD 7-Series chipsets, covering from the enthusiast multi-graphics segment to the value IGP segment, to replace the AMD 480/570/580 chipsets and AMD 690 series chipsets, marking AMD's first enthusiast multi-graphics chipset. Discrete graphics chipsets were launched on November 15, 2007, as part of the codenamed "Spider" desktop platform, and IGP chipsets were launched at a later time in spring 2008 as part of the codenamed "Cartwheel" platform.
AMD returned to the server chipsets market with the AMD 800S series server chipsets. It includes support for up to six SATA 6.0 Gbit/s ports, the C6 power state, which is featured in Fusion processors and AHCI 1.2 with SATA FIS-based switching support. This is a chipset family supporting Phenom processors and Quad FX enthusiast platform (890FX), IGP (890GX). With the advent of AMD's APUs in 2011, traditional northbridge features such as the connection to graphics and the PCI Express controller were incorporated into the APU die. Accordingly, APUs were connected to a single chip chipset, renamed the Fusion Controller Hub (FCH), which primarily provided southbridge functionality. AMD released new chipsets in 2017 to support the release of their new Ryzen products. As the Zen microarchitecture already includes much of the northbridge connectivity, the AM4-based chipsets primarily varied in the number of additional PCI Express lanes, USB connections, and SATA connections available. These AM4 chipsets were designed in conjunction with ASMedia.
Embedded products. Embedded CPUs. In the early 1990s, AMD began marketing a series of embedded system-on-a-chips (SoCs) called AMD Élan, starting with the SC300 and SC310. Both combines a 32-Bit, Am386SX, low-voltage 25 MHz or 33 MHz CPU with memory controller, PC/AT peripheral controllers, real-time clock, PLL clock generators and ISA bus interface. The SC300 integrates in addition two PC card slots and a CGA-compatible LCD controller. They were followed in 1996 by the SC4xx types. Now supporting VESA Local Bus and using the Am486 with up to 100 MHz clock speed. A SC450 with 33 MHz, for example, was used in the Nokia 9000 Communicator. In 1999 the SC520 was announced. Using an Am586 with 100 MHz or 133 MHz and supporting SDRAM and PCI it was the latest member of the series. In February 2002, AMD acquired Alchemy Semiconductor for its Alchemy line of MIPS processors for the hand-held and portable media player markets. On June 13, 2006, AMD officially announced that the line was to be transferred to Raza Microelectronics, Inc., a designer of MIPS processors for embedded applications.
In August 2003, AMD also purchased the Geode business which was originally the Cyrix MediaGX from National Semiconductor to augment its existing line of embedded x86 processor products. During the second quarter of 2004, it launched new low-power Geode NX processors based on the K7 Thoroughbred architecture with speeds of fanless processors and , and processor with fan, of TDP 25 W. This technology is used in a variety of embedded systems (Casino slot machines and customer kiosks for instance), several UMPC designs in Asia markets, and the OLPC XO-1 computer, an inexpensive laptop computer intended to be distributed to children in developing countries around the world. The Geode LX processor was announced in 2005 and is said will continue to be available through 2015. AMD has also introduced 64-bit processors into its embedded product line starting with the AMD Opteron processor. Leveraging the high throughput enabled through HyperTransport and the Direct Connect Architecture these server-class processors have been targeted at high-end telecom and storage applications. In 2007, AMD added the AMD Athlon, AMD Turion, and Mobile AMD Sempron processors to its embedded product line. Leveraging the same 64-bit instruction set and Direct Connect Architecture as the AMD Opteron but at lower power levels, these processors were well suited to a variety of traditional embedded applications. Throughout 2007 and into 2008, AMD has continued to add both single-core Mobile AMD Sempron and AMD Athlon processors and dual-core AMD Athlon X2 and AMD Turion processors to its embedded product line and now offers embedded 64-bit solutions starting with 8 W TDP Mobile AMD Sempron and AMD Athlon processors for fan-less designs up to multi-processor systems leveraging multi-core AMD Opteron processors all supporting longer than standard availability.
The ATI acquisition in 2006 included the Imageon and Xilleon product lines. In late 2008, the entire handheld division was sold off to Qualcomm, who have since produced the Adreno series. Also in 2008, the Xilleon division was sold to Broadcom. In April 2007, AMD announced the release of the M690T integrated graphics chipset for embedded designs. This enabled AMD to offer complete processor and chipset solutions targeted at embedded applications requiring high-performance 3D and video such as emerging digital signage, kiosk, and Point of Sale applications. The M690T was followed by the M690E specifically for embedded applications which removed the TV output, which required Macrovision licensing for OEMs, and enabled native support for dual TMDS outputs, enabling dual independent DVI interfaces. In January 2011, AMD announced the AMD Embedded G-Series Accelerated Processing Unit. This was the first APU for embedded applications. These were followed by updates in 2013 and 2016. In May 2012, AMD Announced the AMD Embedded R-Series Accelerated Processing Unit. This family of products incorporates the Bulldozer CPU architecture, and Discrete-class Radeon HD 7000G Series graphics. This was followed by a system-on-a-chip (SoC) version in 2015 which offered a faster CPU and faster graphics, with support for DDR4 SDRAM memory.
Embedded graphics. AMD builds graphic processors for use in embedded systems. They can be found in anything from casinos to healthcare, with a large portion of products being used in industrial machines. These products include a complete graphics processing device in a compact multi-chip module including RAM and the GPU. ATI began offering embedded GPUs with the E2400 in 2008. Since that time AMD has released regular updates to their embedded GPU lineup in 2009, 2011, 2015, and 2016; reflecting improvements in their GPU technology. Current product lines. CPU and APU products. AMD's portfolio of CPUs and APUs Graphics products. AMD's portfolio of dedicated graphics processors Radeon-branded products. RAM. In 2011, AMD began selling Radeon branded DDR3 SDRAM to support the higher bandwidth needs of AMD's APUs. While the RAM is sold by AMD, it was manufactured by Patriot Memory and VisionTek. This was later followed by higher speeds of gaming oriented DDR3 memory in 2013. Radeon branded DDR4 SDRAM memory was released in 2015, despite no AMD CPUs or APUs supporting DDR4 at the time. AMD noted in 2017 that these products are "mostly distributed in Eastern Europe" and that it continues to be active in the business.
Solid-state drives. AMD announced in 2014 it would sell Radeon branded solid-state drives manufactured by OCZ with capacities up to 480 GB and using the SATA interface. Technologies. CPU hardware. technologies found in AMD CPU/APU and other products include: Graphics hardware. technologies found in AMD GPU products include: Software. AMD has made considerable efforts towards opening its software tools above the firmware level in the past decade. For the following mentions, software not expressely stated as being free can be assumed to be proprietary. Distribution. AMD Radeon Software is the default channel for official software distribution from AMD. It includes both free and proprietary software components, and supports both Microsoft Windows and Linux. GPU. Most notable public AMD software is on the GPU side. AMD has opened both its graphic and compute stacks: Production and fabrication. Previously, AMD produced its chips at company-owned semiconductor foundries. AMD pursued a strategy of collaboration with other semiconductor manufacturers IBM and Motorola to co-develop production technologies. AMD's founder Jerry Sanders termed this the "Virtual Gorilla" strategy to compete with Intel's significantly greater investments in fabrication.
In 2008, AMD spun off its chip foundries into an independent company named GlobalFoundries. This breakup of the company was attributed to the increasing costs of each process node. The Emirate of Abu Dhabi purchased the newly created company through its subsidiary Advanced Technology Investment Company (ATIC), purchasing the final stake from AMD in 2009. With the spin-off of its foundries, AMD became a fabless semiconductor manufacturer, designing products to be produced at for-hire foundries. Part of the GlobalFoundries spin-off included an agreement with AMD to produce some number of products at GlobalFoundries. Both prior to the spin-off and after AMD has pursued production with other foundries including TSMC and Samsung. It has been argued that this would reduce risk for AMD by decreasing dependence on any one foundry which has caused issues in the past. In 2018, AMD started shifting the production of their CPUs and GPUs to TSMC, following GlobalFoundries' announcement that they were halting development of their 7 nm process. AMD revised their wafer purchase requirement with GlobalFoundries in 2019, allowing AMD to freely choose foundries for 7 nm nodes and below, while maintaining purchase agreements for 12 nm and above through 2021.
Corporate affairs. Business trends. The key trends for AMD are (as of the financial year ending in late December): Partnerships. AMD uses strategic industry partnerships to further its business interests and to rival Intel's dominance and resources: Litigation with Intel. AMD has a long history of litigation with former (and current) partner and x86 creator Intel. Sponsorships. AMD's sponsorship of Formula 1 racing began in 2002 and since 2020 has sponsored the Mercedes-AMG Petronas team. AMD was also a sponsor of the BMW Sauber and Scuderia Ferrari Formula 1 teams together with Intel, Vodafone, AT&T, Pernod Ricard and Diageo. On 18 April 2018, AMD began a multi-year sponsorship with Scuderia Ferrari. In February 2020, just prior to the start of the 2020 race season, the Mercedes Formula 1 team announced it was adding AMD to its sponsorship portfolio. AMD began a sponsorship deal with Victory Five (V5) for the League of Legends Pro League (LPL) in 2022. AMD was a sponsor of the Chinese Dota Pro Circuit together with Perfect World. In February 2024, AMD was a Diamond sponsor for the World Artificial Intelligence Cannes Festival (WAICF). AMD was a Platinum sponsor for the HPE Discover 2024, an event hosted by Hewlett Packard Enterprise to showcase technology for government and business customers. The event was held from 17 to 20 June 2024 in Las Vegas.
Albrecht Dürer Albrecht Dürer ( , ;; 21 May 1471 – 6 April 1528), sometimes spelled in English as Durer or Duerer, was a German painter, printmaker, and theorist of the German Renaissance. Born in Nuremberg, Dürer established his reputation and influence across Europe in his twenties due to his high-quality woodcut prints. He was in contact with the major Italian artists of his time, including Raphael, Giovanni Bellini and Leonardo da Vinci, and from 1512 was patronized by Emperor Maximilian I. Dürer's vast body of work includes engravings, his preferred technique in his later prints, altarpieces, portraits and self-portraits, watercolours and books. The woodcuts series are stylistically more Gothic than the rest of his work, but revolutionised the potential of that medium, while his extraordinary handling of the burin expanded especially the tonal range of his engravings; well-known engravings include the three "Meisterstiche" (master prints) "Knight, Death and the Devil" (1513), "Saint Jerome in his Study" (1514), and "Melencolia I" (1514). His watercolours mark him as one of the first European landscape artists.
Dürer's introduction of classical motifs and of the nude into Northern art, through his knowledge of Italian artists and German humanists, has secured his reputation as one of the most important figures of the Northern Renaissance. This is reinforced by his theoretical treatises, which involve principles of mathematics for linear perspective and body proportions. Biography. Early life (1471–1490). Dürer was born on 21 May 1471, the third child and second son of Albrecht Dürer the Elder and Barbara Holper, who married in 1467. Albrecht Dürer the Elder (originally Albrecht Ajtósi) was a successful goldsmith who by 1455 had moved to Nuremberg from Ajtós, near Gyula in Hungary. He married Barbara, his master's daughter, when he himself qualified as a master. Her mother, Klinga Öllinger had some roots in Hungary too, as she was born in Sopron. The couple had eighteen children together, of which only three survived. Hans Dürer (1490–1534), also became a painter, trained under the older Albrecht. The other surviving brother, Endres Dürer (1484–1555), took over their father's business and was a master goldsmith. The German name "Dürer" is a translation from the Hungarian, "Ajtósi". Initially, it was "Türer", meaning doormaker, which is "ajtós" in Hungarian (from "ajtó", meaning door). A door is featured in the coat-of-arms the family acquired. Albrecht Dürer the Younger later changed "Türer", his father's diction of the family's surname, to "Dürer", to adapt to the local Nuremberg dialect.
Because Dürer left autobiographical writings and was widely known by his mid-twenties, his life is well documented. After a few years of school, Dürer learned the basics of goldsmithing and drawing from his father. Though his father wanted him to continue his training as a goldsmith, he showed such a precocious talent in drawing that he was allowed to start as an apprentice to Michael Wolgemut at the age of fifteen in 1486. A self-portrait, a drawing in silverpoint, is dated 1484 (Albertina, Vienna) "when I was a child", as his later inscription says. The drawing is one of the earliest surviving children's drawings of any kind, and, as Dürer's Opus One, has helped define his oeuvre as deriving from, and always linked to, himself. Wolgemut was the leading artist in Nuremberg at the time, with a large workshop producing a variety of works of art, in particular woodcuts for books. Nuremberg was then an important and prosperous city, a centre for publishing and many luxury trades. It had strong links with Italy, especially Venice, a relatively short distance across the Alps.
Dürer's godfather Anton Koberger left goldsmithing to become a printer and publisher in the year of Dürer's birth. He became the most successful publisher in Germany, eventually owning twenty-four printing-presses and a number of offices in Germany and abroad. Koberger's most famous publication was the "Nuremberg Chronicle", published in 1493 in German and Latin editions. It contained an unprecedented 1,809 woodcut illustrations (albeit with many repeated uses of the same block) by the Wolgemut workshop. Dürer may have worked on some of these, as the work on the project began while he was with Wolgemut. "Wanderjahre" and marriage (1490–1494). After completing his apprenticeship, Dürer followed the common German custom of taking "Wanderjahre"—in effect gap years—in which the apprentice learned skills from other masters, their local tradition and individual styles; Dürer was to spend about four years away. He left in 1490, possibly to work under Martin Schongauer, the leading engraver of Northern Europe, but who died shortly before Dürer's arrival at Colmar in 1492. It is unclear where Dürer travelled in the intervening period, though it is likely that he went to Frankfurt and the Netherlands. In Colmar, Dürer was welcomed by Schongauer's brothers, the goldsmiths Caspar and Paul and the painter Ludwig. Later that year, Dürer travelled to Basel to stay with another brother of Martin Schongauer, the goldsmith Georg. In 1493 Dürer went to Strasbourg, where he would have experienced the sculpture of Nikolaus Gerhaert. Dürer's first painted self-portrait (now in the Louvre) was painted at this time, probably to be sent back to his fiancée in Nuremberg.
Very soon after his return to Nuremberg, on 7 July 1494, at the age of 23, Dürer was married to Agnes Frey following an arrangement made during his absence. Agnes was the daughter of a prominent brass worker (and amateur harpist) in the city. However, no children resulted from the marriage, and with Albrecht the Dürer name died out. The marriage between Agnes and Albrecht was believed not to be a generally happy one, as indicated by a letter of Dürer in which he quipped to Willibald Pirckheimer in a rough tone about his wife, calling her an "old crow" and made other vulgar remarks. Pirckheimer also made no secret of his antipathy towards Agnes, describing her as a miserly shrew with a bitter tongue, who helped cause Dürer's death at a young age. It has been hypothesized by many scholars that Albrecht was bisexual or homosexual, due to the recurrence of allegedly homoerotic themes in some of his works (e.g. "The Men's Bath"), and the nature of his correspondence with close friends. First journey to Italy (1494–1495).
Within three months of his marriage, Dürer left for Italy, alone, perhaps stimulated by an outbreak of plague in Nuremberg. He made watercolour sketches as he traveled over the Alps. Some have survived and others may be deduced from accurate landscapes of real places in his later work, for example his engraving "Nemesis". In Italy, he went to Venice to study its more advanced artistic world. Through Wolgemut's tutelage, Dürer had learned how to make prints in drypoint and design woodcuts in the German style, based on the works of Schongauer and the Housebook Master. He also would have had access to some Italian works in Germany, but the two visits he made to Italy had an enormous influence on him. He wrote that Giovanni Bellini was the oldest and still the best of the artists in Venice. His drawings and engravings show the influence of others, notably Antonio del Pollaiuolo, with his interest in the proportions of the body; Lorenzo di Credi; and Andrea Mantegna, whose work he produced copies of while training. Dürer probably also visited Padua and Mantua on this trip.
Return to Nuremberg (1495–1505). On his return to Nuremberg in 1495, Dürer opened his own workshop (being married was a requirement for this). Over the next five years, his style increasingly integrated Italian influences into underlying Northern forms. Arguably his best works in the first years of the workshop were his woodcut prints, mostly religious, but including secular scenes such as "The Men's Bath" (). These were larger and more finely cut than the great majority of German woodcuts hitherto, and far more complex and balanced in composition. It is now thought unlikely that Dürer cut any of the woodblocks himself; this task would have been performed by a specialist craftsman. However, his training in Wolgemut's studio, which made many carved and painted altarpieces and both designed and cut woodblocks for woodcut, evidently gave him great understanding of what the technique could be made to produce, and how to work with block cutters. Dürer either drew his design directly onto the woodblock itself, or glued a paper drawing to the block. Either way, his drawings were destroyed during the cutting of the block.
His series of sixteen designs for the "Apocalypse" is dated 1498, as is his engraving of "St. Michael Fighting the Dragon". He made the first seven scenes of the "Great Passion" in the same year, and a little later, a series of eleven on the Holy Family and saints. The "Seven Sorrows Polyptych", commissioned by Frederick III of Saxony in 1496, was executed by Dürer and his assistants c. 1500. In 1502, Dürer's father died. Around 1503–1505 Dürer produced the first 17 of a set illustrating the "Life of the Virgin", which he did not finish for some years. Neither these nor the "Great Passion" were published as sets until several years later, but prints were sold individually in considerable numbers. During the same period Dürer perfected the difficult art of using the burin to make engravings. Most likely he had learned this skill during his early training with his father, as it was also an essential skill of the goldsmith. In 1496 he executed the "Prodigal Son", which the Italian Renaissance art historian Giorgio Vasari singled out for praise some decades later, noting its Germanic quality. He was soon producing some spectacular and original images, notably "Nemesis" (1502), "The Sea Monster" (1498), and "Saint Eustace" (), with a highly detailed landscape background and animals. His landscapes of this period, such as "Pond in the Woods" and "Willow Mill", are quite different from his earlier watercolours. There is a much greater emphasis on capturing atmosphere, rather than depicting topography. He made a number of Madonnas, single religious figures, and small scenes with comic peasant figures. Prints are highly portable and these works made Dürer famous throughout the main artistic centres of Europe within a very few years.
The Venetian artist Jacopo de' Barbari, whom Dürer had met in Venice, visited Nuremberg in 1500, and Dürer said that he learned much about the new developments in perspective, anatomy, and proportion from him. To Dürer it seemed that De' Barbari was unwilling to explain everything he knew, so he began his own studies, which would become a lifelong preoccupation. A series of extant drawings show Dürer's experiments in human proportion, leading to the famous engraving of "Adam and Eve" (1504), which shows his subtlety while using the burin in the texturing of flesh surfaces. This is the only existing engraving signed with his full name. Dürer created large numbers of preparatory drawings, especially for his paintings and engravings, and many survive, most famously the "Betende Hände" ("Praying Hands") from circa 1508, a study for an apostle in the Heller altarpiece. He continued to make images in watercolour and bodycolour (usually combined), including a number of still lifes of meadow sections or animals, including his "Young Hare" (1502) and the "Great Piece of Turf" (1503).
Second journey to Italy (1505–1507). In Italy, he returned to painting, at first producing a series of works executed in tempera on linen. These include portraits and altarpieces, notably, the Paumgartner altarpiece and the "Adoration of the Magi". In early 1506, he returned to Venice and stayed there until the spring of 1507. It was in Venice that he took up the material of blue paper, which he used to execute preparatory drawing for paintings he completed there in 1505–1507. By this time Dürer's engravings had attained great popularity and were being copied. In Venice he was given a valuable commission from the emigrant German community for the church of San Bartolomeo. This was the altar-piece known as the "Feast of the Rosary" (or the "Feast of Rose Garlands"). It shows Pope Julius II and Emperor Maximilian I, peacefully kneeling in adoration before her throne, both with their crowns taken off. It also includes portraits of members of Venice's German community and of Dürer himself on the upper right holding a designation of his authorship. Besides the Flemish verism in the depiction of the greenery and the garments, and the use of his own hues, the altar-piece shows a strong Italian influence. It was later acquired by the Emperor Rudolf II and taken to Prague.
Nuremberg and the masterworks (1507–1520). Dürer returned to Nuremberg by mid-1507, remaining in Germany until 1520. His reputation had spread throughout Europe and he was on friendly terms and in communication with many of the major artists including Raphael. Between 1507 and 1511 Dürer worked on some of his most celebrated paintings: "Adam and Eve" (1507), "Martyrdom of the Ten Thousand" (1508, for Frederick of Saxony), "Virgin with the Iris" (1508), the altarpiece "Assumption of the Virgin" (1509, for Jacob Heller of Frankfurt), and "Adoration of the Trinity" (1511, for Matthaeus Landauer). During this period he also completed two woodcut series, the "Great Passion" and the "Life of the Virgin", both published in 1511 together with a second edition of the "Apocalypse" series. The post-Venetian woodcuts show Dürer's development of chiaroscuro modelling effects, creating a mid-tone throughout the print to which the highlights and shadows can be contrasted. Other works from this period include the thirty-seven "Little Passion" woodcuts, published in 1511, and a set of fifteen small engravings on the same theme in 1512. Complaining that painting did not make enough money to justify the time spent when compared to his prints, he produced no paintings from 1513 to 1516. In 1513 and 1514 Dürer created his three most famous engravings: "Knight, Death and the Devil" (1513, probably based on Erasmus's "Handbook of a Christian Knight"), "St. Jerome in His Study", and the much-debated "Melencolia I" (both 1514, the year Dürer's mother died). Further outstanding pen and ink drawings of Dürer's period of art work of 1513 were drafts for his friend Pirckheimer. These drafts were later used to design Lusterweibchen chandeliers, combining an antler with a wooden sculpture.
In 1515, he created his "woodcut of a Rhinoceros" which had arrived in Lisbon from a written description and sketch by another artist, without ever seeing the animal himself. An image of the Indian rhinoceros, the image has such force that it remains one of his best-known and was still used in some German school science text-books as late as last century. In the years leading to 1520 he produced a wide range of works, including the woodblocks for the first western printed star charts in 1515 and portraits in tempera on linen in 1516. His only experiments with etching came in this period, producing five between 1515–1516 and a sixth in 1518; a technique he may have abandoned as unsuited to his aesthetic of methodical, classical form. Patronage of Maximilian I. From 1512, Maximilian I became Dürer's major patron. He commissioned "The Triumphal Arch", a vast work printed from 192 separate blocks, the symbolism of which is partly informed by Pirckheimer's translation of Horapollo's "Hieroglyphica". The design program and explanations were devised by Johannes Stabius, the architectural design by the master builder and court-painter Jörg Kölderer and the woodcutting itself by Hieronymous Andreae, with Dürer as designer-in-chief. "The Arch" was followed by "The Triumphal Procession" completed c. 1512.
Dürer worked with pen on the marginal images for an edition of the Emperor's printed prayer book; these were quite unknown until facsimiles were published in 1808 as part of the first book published in lithography. Dürer's work on the book was halted for an unknown reason, and the decoration was continued by artists including Lucas Cranach the Elder and Hans Baldung. Dürer also made several portraits of the Emperor, including one shortly before Maximilian's death in 1519. Maximilian was a very cash-strapped prince who sometimes failed to pay, yet turned out to be Dürer's most important patron. In his court, artists and learned men were respected, which was not common at that time (later, Dürer commented that in Germany, as a non-noble, he was treated as a parasite). Pirckheimer (who he met in 1495, before entering the service of Maximilian) was also an important personage in the court and great cultural patron, who had a strong influence on Dürer as his tutor in classical knowledge and humanistic critical methodology, as well as collaborator. In Maximilian's court, Dürer also collaborated with a great number of other brilliant artists and scholars of the time who became his friends, like Johannes Stabius, Konrad Peutinger, Conrad Celtes, and Hans Tscherte (an imperial architect).
Dürer was proud of his ability. When the emperor tried to sketch Dürer an idea on charcoa, Dürer took the material from Maximilian's hand, finished the drawing and told him: "This is my scepter." On another occasion, Maximilian noticed that the ladder Dürer used was too short and unstable, thus told a noble to hold it for him. The noble refused, saying that it was beneath him to serve a non-noble. Maximilian then came to hold the ladder himself, and told the noble that he could make a noble out of a peasant any day, but he could not make an artist like Dürer out of a noble. This story and a 1849 painting depicting it by have become relevant recently. This nineteenth-century painting shows Dürer painting a mural at St. Stephen's Cathedral, Vienna. Apparently, this reflects a seventeenth-century "artists' legend" about the previously mentioned encounter (in which the emperor held the ladder) – that this encounter corresponds with the period Dürer was working on the Viennese murals. In 2020, during restoration work, art connoisseurs discovered a piece of handwriting now attributed to Dürer, suggesting that the Nuremberg master had actually participated in creating the murals at St. Stephen's Cathedral. In the recent 2022 Dürer exhibition in Nuremberg (in which the drawing technique is also traced and connected to Dürer's other works), the identity of the commissioner is discussed. Now the painting of Siegert (and the legend associated with it) is used as evidence to suggest that this was Maximilian. Dürer is historically recorded to have entered the emperor's service in 1511, and the mural's date is calculated to be around 1505, but it is possible they have known and worked with each other earlier than 1511.
Cartographic and astronomical works. Dürer's exploration of space led to a relationship and cooperation with the court astronomer Johannes Stabius. Stabius also often acted as Dürer's and Maximilian's go-between for their financial problems. In 1515 Dürer and Stabius created the first world map projected on a solid geometric sphere. Also in 1515, Stabius, Dürer and the astronomer produced the first planispheres of both southern and northerns hemispheres, as well as the first printed celestial maps, which prompted the revival of interest in the field of uranometry throughout Europe. Journey to the Netherlands (1520–1521). Maximilian's death came at a time when Dürer was concerned he was losing "my sight and freedom of hand" (perhaps caused by arthritis) and increasingly affected by the writings of Martin Luther. In July 1520 Dürer made his fourth and last major journey, to renew the Imperial pension Maximilian had given him and to secure the patronage of the new emperor, Charles V, who was to be crowned at Aachen. Dürer journeyed with his wife and her maid via the Rhine to Cologne and then to Antwerp, where he was well received and produced numerous drawings in silverpoint, chalk and charcoal. In addition to attending the coronation, he visited Cologne (where he admired the painting of Stefan Lochner), Nijmegen, 's-Hertogenbosch, Bruges (where he saw Michelangelo's "Madonna of Bruges"), Ghent (where he admired Jan van Eyck's "Ghent Altarpiece"), and Zeeland.
Dürer took a large stock of prints with him and wrote in his diary to whom he gave, exchanged or sold them, and for how much. This provides rare information of the monetary value placed on prints at this time. Unlike paintings, their sale was very rarely documented. While providing valuable documentary evidence, Dürer's Netherlandish diary also reveals that the trip was not a profitable one. For example, Dürer offered his last portrait of Maximilian to his daughter, Margaret of Austria, but eventually traded the picture for some white cloth after Margaret disliked the portrait and declined to accept it. During this trip he also met Bernard van Orley, Jan Provoost, Gerard Horenbout, Jean Mone, Joachim Patinir and Tommaso Vincidor, though he did not, it seems, meet Quentin Matsys. Having secured his pension, Dürer returned home in July 1521, having caught an undetermined illness, which afflicted him for the rest of his life, and greatly reduced his rate of work. Final years, Nuremberg (1521–1528). On his return to Nuremberg, Dürer worked on a number of grand projects with religious themes, including a crucifixion scene and a , though neither was completed. This may have been due in part to his declining health, but perhaps also because of the time he gave to the preparation of his theoretical works on geometry and perspective, the proportions of men and horses, and fortification.
However, one consequence of this shift in emphasis was that during the last years of his life, Dürer produced comparatively little as an artist. In painting, there was only a portrait of , a , , and two panels showing and beside him. This last great work, "the Four Apostles", was given by Dürer to the City of Nuremberg—although he was given 100 guilders in return. As for engravings, Dürer's work was restricted to portraits and illustrations for his treatise. The portraits include his boyhood friend Willibald Pirckheimer, Cardinal-Elector Albert of Mainz; Frederick the Wise, elector of Saxony; Philipp Melanchthon, and Erasmus of Rotterdam. For those of the Cardinal, Melanchthon, and Dürer's final major work, a drawn portrait of the Nuremberg patrician Ulrich Starck, Dürer depicted the sitters in profile. Despite complaining of his lack of a formal classical education, Dürer was greatly interested in intellectual matters and learned much from Willibald Pirckheimer, whom he no doubt consulted on the content of many of his images. He also derived great satisfaction from his friendships and correspondence with Erasmus and other scholars. Dürer succeeded in producing two books during his lifetime. "The Four Books on Measurement" were published at Nuremberg in 1525 and was the first book for adults on mathematics in German, as well as being cited later by Galileo and Kepler. The other, a work on city fortifications, was published in 1527. "The Four Books on Human Proportion" were published posthumously, shortly after his death in 1528.
Dürer died in Nuremberg at the age of 56, leaving an estate valued at 6,874 florins – a considerable sum. He is buried in the Johannisfriedhof cemetery. His large house (purchased in 1509 from the heirs of the astronomer Bernhard Walther), where his workshop was located and where his widow lived until her death in 1539, remains a prominent Nuremberg landmark. Dürer and the Reformation. Dürer's writings suggest that he may have been sympathetic to Luther's ideas, though it is unclear if he ever left the Catholic Church. Dürer wrote of his desire to draw Luther in his diary in 1520: "And God help me that I may go to Dr. Martin Luther; thus I intend to make a portrait of him with great care and engrave him on a copper plate to create a lasting memorial of the Christian man who helped me overcome so many difficulties." In a letter to Nicholas Kratzer in 1524, Dürer wrote, "because of our Christian faith we have to stand in scorn and danger, for we are reviled and called heretics". Most tellingly, Pirckheimer wrote in a letter to Johann Tscherte in 1530: "I confess that in the beginning I believed in Luther, like our Albert of blessed memory ... but as anyone can see, the situation has become worse." Dürer may even have contributed to the Nuremberg City Council's mandating Lutheran sermons and services in March 1525. Notably, Dürer had contacts with various reformers, such as Zwingli, Andreas Karlstadt, Melanchthon, Erasmus and Cornelius Grapheus from whom Dürer received Luther's "Babylonian Captivity" in 1520. Yet Erasmus and C. Grapheus are better said to be Catholic change agents. Also, from 1525, "the year that saw the peak and collapse of the Peasants' War, the artist can be seen to distance himself somewhat from the [Lutheran] movement..."
Dürer's later works have also been claimed to show Protestant sympathies. His 1523 "The Last Supper" woodcut has often been understood to have an evangelical theme, focusing as it does on Christ espousing the Gospel, as well as the inclusion of the Eucharistic cup, an expression of Protestant utraquism, although this interpretation has been questioned. The delaying of the engraving of St. Philip, completed in 1523 but not distributed until 1526, may have been due to Dürer's uneasiness with images of saints; even if Dürer was not an iconoclast, in his last years he evaluated and questioned the role of art in religion. Theoretical works. In all his theoretical works, in order to communicate his theories in the German language rather than in Latin, Dürer used graphic expressions based on a vernacular, craftsmen's language. For example, ("snail-line") was his term for a spiral form. Thus, Dürer contributed to the expansion in German prose which Luther had begun with his translation of the Bible. "Four Books on Measurement".
Dürer's work on geometry is called the "Four Books on Measurement" ("Underweysung der Messung mit dem Zirckel und Richtscheyt" or "Instructions for Measuring with Compass and Ruler"). The first book focuses on linear geometry. Dürer's geometric constructions include helices, conchoids and epicycloids. He also draws on Apollonius, and Johannes Werner's of 1522. The second book moves onto two-dimensional geometry, i.e. the construction of regular polygons. Here Dürer favours the methods of Ptolemy over Euclid. The third book applies these principles of geometry to architecture, engineering and typography. In architecture Dürer cites Vitruvius but elaborates his own classical designs and columns. In typography, Dürer depicts the geometric construction of the Latin alphabet, relying on Italian precedent. However, his construction of the Gothic alphabet is based upon an entirely different modular system. The fourth book completes the progression of the first and second by moving to three-dimensional forms and the construction of polyhedra. Here Dürer discusses the five Platonic solids, as well as seven Archimedean semi-regular solids, as well as several of his own invention.
"Four Books on Human Proportion". Dürer's work on human proportions is called the "Four Books on Human Proportion" ("Vier Bücher von menschlicher Proportion") of 1528. The first book was mainly composed by 1512/13 and completed by 1523, showing five differently constructed types of both male and female figures, all parts of the body expressed in fractions of the total height. Dürer based these constructions on both Vitruvius and empirical observations of "two to three hundred living persons", in his own words. The second book includes eight further types, broken down not into fractions but an Albertian system, which Dürer probably learned from Francesco di Giorgio's of 1525. In the third book, Dürer gives principles by which the proportions of the figures can be modified, including the mathematical simulation of convex and concave mirrors; here Dürer also deals with human physiognomy. The fourth book is devoted to the theory of movement.
"Book on Fortification". In 1527, Dürer also published "Various Lessons on the Fortification of Cities, Castles, and Localities" ("Etliche Underricht zu Befestigung der Stett, Schloss und Flecken"). It was printed in Nuremberg, probably by Hieronymus Andreae and reprinted in 1603 by Johan Janssenn in Arnhem. In 1535 it was also translated into Latin as "On Cities, Forts, and Castles, Designed and Strengthened by Several Manners: Presented for the Most Necessary Accommodation of War" ("De vrbibus, arcibus, castellisque condendis, ac muniendis rationes aliquot : praesenti bellorum necessitati accommodatissimae"), published by Christian Wechel (Wecheli/Wechelus) in Paris. Fencing. Dürer created many sketches and woodcuts of soldiers and knights over the course of his life. His most significant martial works, however, were made in 1512 as part of his efforts to secure the patronage of Maximilian I. Using existing manuscripts from the "Nuremberg Group" as his reference, his workshop produced the extensive "Οπλοδιδασκαλια sive Armorvm Tractandorvm Meditatio Alberti Dvreri" ("Weapon Training, or Albrecht Dürer's Meditation on the Handling of Weapons", MS 26-232). Another manuscript based on the Nuremberg texts as well as one of Hans Talhoffer's works, the untitled "Berlin Picture Book" (Libr.Pict.A.83), is also thought to have originated in his workshop around this time. These sketches and watercolours show the same careful attention to detail and human proportion as Dürer's other work, and his illustrations of grappling, long sword, dagger, and messer are among the highest-quality in any fencing manual.
Legacy and influence. Dürer exerted a huge influence on the artists of succeeding generations, especially in printmaking, the medium through which his contemporaries mostly experienced his art, as his paintings were predominantly in private collections located in only a few cities. His success in spreading his reputation across Europe through prints was undoubtedly an inspiration for major artists such as Raphael, Titian, and Parmigianino, all of whom collaborated with printmakers to promote and distribute their work. His engravings seem to have had an intimidating effect upon his German successors; the "Little Masters" who attempted few large engravings but continued Dürer's themes in small, rather cramped compositions. Lucas van Leyden was the only Northern European engraver to successfully continue to produce large engravings in the first third of the 16th century. The generation of Italian engravers who trained in the shadow of Dürer all either directly copied parts of his landscape backgrounds (Giulio Campagnola, Giovanni Battista Palumba, Benedetto Montagna and Cristofano Robetta), or whole prints (Marcantonio Raimondi and Agostino Veneziano). However, Dürer's influence became less dominant after 1515, when Marcantonio perfected his new engraving style, which in turn travelled over the Alps to also dominate Northern engraving.
Dürer had relatively little influence in Italy, where probably only his altarpiece in Venice was seen, and his German successors were less effective in blending German and Italian styles. His intense and self-dramatizing self-portraits have continued to have a strong influence up to the present, especially on painters in the 19th and 20th century who desired a more dramatic portrait style. Dürer has never fallen from critical favour, and there have been significant revivals of interest in his works in Germany in the "Dürer Renaissance" of about 1570 to 1630, in the early nineteenth century, and in German nationalism from 1870 to 1945. The Lutheran Church commemorates Dürer annually on 6 April, along with Michelangelo, Lucas Cranach the Elder and Hans Burgkmair. In 1993, two of Dürer's drawings – "Women's Bathhouse", valued at about $10 million, and "Sitting Mary With Child" – along with other works of art were stolen from the National Art Museum of Azerbaijan. The drawings were later recovered.
Australian rules football Australian rules football, also called Australian football or Aussie rules, or more simply football or footy, is a contact sport played between two teams of 18 players on an oval field, often a modified cricket ground. Points are scored by kicking the oval ball between the central goal posts (worth six points), or between a central and outer post (worth one point, otherwise known as a "behind"). During general play, players may position themselves anywhere on the field and use any part of their bodies to move the ball. The primary methods are kicking, handballing and running with the ball. There are rules on how the ball can be handled; for example, players running with the ball must intermittently bounce or touch it on the ground. Throwing the ball is not allowed, and players must not get caught holding the ball. A distinctive feature of the game is the mark, where players anywhere on the field who catch the ball from a kick (with specific conditions) are awarded unimpeded possession. Possession of the ball is in dispute at all times except when a free kick or mark is paid. Players can tackle using their hands or use their whole body to obstruct opponents. Dangerous physical contact (such as pushing an opponent in the back), interference when marking, and deliberately slowing the play are discouraged with free kicks, distance penalties, or suspension for a certain number of matches depending on the severity of the infringement. The game features frequent physical contests, spectacular marking, fast movement of both players and the ball, and high scoring.
The sport's origins can be traced to football matches played in Melbourne, Victoria, in 1858, inspired by English public school football games. Seeking to develop a game more suited to adults and Australian conditions, the Melbourne Football Club published the first laws of Australian football in May 1859. Australian football has the highest spectator attendance and television viewership of all sports in Australia, while the Australian Football League (AFL), the sport's only fully professional competition, is the nation's wealthiest sporting body. The AFL Grand Final, held annually at the Melbourne Cricket Ground, is the second-highest-attended club championship event in the world. The sport is also played at amateur level in many countries and in several variations. Its rules are governed by the AFL Commission with the advice of the AFL's Laws of the Game Committee. Name. Australian rules football is known by several nicknames, including Aussie rules, football and footy. In some regions, where other codes of football are more popular, the sport is most often called AFL after the Australian Football League, while the league itself also uses this name for local competitions in some areas.
History. Origins. Primitive forms of football were played sporadically in the Australian colonies in the first half of the 19th century. Compared to cricket and horse racing, football was considered a mere "amusement" by colonists at the time, and while little is known about these early one-off games, evidence does not support a causal link with Australian football. In Melbourne, in 1858, in a move that would help to shape Australian football in its formative years, private schools (then termed "public schools" in accordance with nomenclature in England) began organising football games inspired by precedents at English public schools. The earliest match, held on 15 June, was between Melbourne Grammar and St Kilda Grammar.
Since the 1920s, it has been suggested that Australian football may have been derived from the Irish sport of Gaelic football. However, there is no archival evidence in favour of a Gaelic influence, and the style of play shared between the two modern codes appeared in Australia long before the Irish game evolved in a similar direction. Another theory, first proposed in 1983, posits that Wills, having grown up among Aboriginals in Victoria, may have seen or played the Aboriginal ball game of Marn Grook, and incorporated some of its features into early Australian football. There is only circumstantial evidence that he knew of the game, and according to biographer Greg de Moore's research, Wills was "almost solely influenced by his experience at Rugby School". First rules. A loosely organised Melbourne side, captained by Wills, played against other football enthusiasts in the winter and spring of 1858. The following year, on 14 May, the Melbourne Football Club was officially established, making it one of the world's oldest football clubs. Three days later, Wills, Hammersley, Thompson and teacher Thomas H. Smith met near the MCG at the Parade Hotel, owned by Bryant, and drafted ten rules: "The Rules of the Melbourne Football Club". These are the laws from which Australian football evolved. The club aimed to create a simple code suited to the hard playing surfaces around Melbourne, and to eliminate the roughest aspects of English school games—such as "hacking" (shin-kicking) in Rugby School football—to reduce the risk of injuries to working men. In another significant departure from English public school football, the Melbourne rules omitted any offside law. "The new code was as much a reaction against the school games as influenced by them", writes Mark Pennings. The rules were distributed throughout the colony; Thompson in particular did much to promote the new code in his capacity as a journalist.
Early competition in Victoria. Following Melbourne's lead, Geelong and Melbourne University also formed football clubs in 1859. While many early Victorian teams participated in one-off matches, most had not yet formed clubs for regular competition. A South Yarra club devised its own rules. To ensure the supremacy of the Melbourne rules, the first-club level competition in Australia, the Caledonian Society's Challenge Cup (1861–64), stipulated that only the Melbourne rules were to be used. This law was reinforced by the Athletic Sports Committee (ASC), which ran a variation of the Challenge Cup in 1865–66. With input from other clubs, the rules underwent several minor revisions, establishing a uniform code known as "Victorian rules". In 1866, the "first distinctively Victorian rule", the running bounce, was formalised at a meeting of club delegates chaired by H. C. A. Harrison, an influential pioneer who took up football in 1859 at the invitation of Wills, his cousin. The game around this time was defensive and low-scoring, played low to the ground in congested rugby-style scrimmages. The typical match was a 20-per-side affair, played with a ball that was roughly spherical, and lasted until a team scored two goals. The shape of the playing field was not standardised; matches often took place in rough, tree-spotted public parks, most notably the Richmond Paddock (Yarra Park), known colloquially as the Melbourne Football Ground. Wills argued that the turf of cricket fields would benefit from being trampled upon by footballers in winter, and, as early as 1859, football was allowed on the MCG. However, cricket authorities frequently prohibited football on their grounds until the 1870s, when they saw an opportunity to capitalise on the sport's growing popularity. Football gradually adapted to an oval-shaped field, and most grounds in Victoria expanded to accommodate the dual purpose—a situation that continues to this day.
Spread to other colonies. Football became organised in South Australia in 1860 with the formation of the Adelaide Football Club, the oldest football club in Australia outside Victoria. It devised its own rules, and, along with other Adelaide-based clubs, played a variety of codes until 1876, when they uniformly adopted most of the Victorian rules, with South Australian football pioneer Charles Kingston noting their similarity to "the old Adelaide rules". Similarly, Tasmanian clubs quarrelled over different rules until they adopted a slightly modified version of the Victorian game in 1879. The South Australian Football Association (SAFA), the sport's first governing body, formed on 30 April 1877, firmly establishing Victorian rules as the preferred code in that colony. The Victorian Football Association (VFA) formed the following month. Clubs began touring the colonies in the late 1870s, and in 1879 the first intercolonial match took place in Melbourne between Victoria and South Australia. In 1883, delegates representing the football associations of South Australia, Tasmania, Victoria and Queensland met to standardise the code across Australia. New rules such as holding the ball led to a "golden era" of fast, long-kicking and high-marking football in the 1880s, a time which also saw players such as George Coulthard achieve superstardom, as well as the rise of professionalism, particularly in Victoria and Western Australia, where the code took hold during a series of gold rushes. Likewise, when New Zealand experienced a gold rush, the sport arrived with a rapid influx of Australian miners. Now known as Australian rules or Australasian rules, the sport became the first football code to develop mass spectator appeal, attracting world record attendances for sports viewing and gaining a reputation as "the people's game".
Australian rules football reached Queensland and New South Wales as early as 1866; the sport experienced a period of dominance in the former, and in the latter, several regions remain strongholds of Australian rules, such as the Riverina. However, by the late 1880s, rugby football had become the dominant code in both colonies, as well as in New Zealand. This shift was largely due to rugby's spread with British migration, regional rivalries and the lack of strong local governing bodies. In the case of Sydney, denial of access to grounds, the influence of university headmasters from Britain who favoured rugby, and the loss of players to other codes inhibited the game's growth. Emergence of the VFL. In 1896, delegates from six of the wealthiest VFA clubs—Carlton, Essendon, Fitzroy, Geelong, Melbourne and South Melbourne—met to discuss the formation of a breakaway professional competition. Later joined by Collingwood and St Kilda, the clubs formed the Victorian Football League (VFL), which held its inaugural season in 1897. The VFL's popularity grew rapidly as it made several innovations, such as instituting a finals system, reducing teams from 20 to 18 players, and introducing the behind as a score. Richmond and University joined the VFL in 1908, and by 1925, with the addition of Hawthorn, Footscray and North Melbourne, it had become the preeminent league in the country and would take a leading role in many aspects of the sport.
Interstate football and the World Wars. The time around the federation of the Australian colonies in 1901 saw Australian rules undergo a revival in New South Wales, New Zealand and Queensland. In 1903, both the Queensland Australian Football League and the NSW Australian Football Association were established, and in New Zealand, as it moved towards becoming a dominion, leagues were also established in the major cities. This renewed popularity helped encourage the formation of the Australasian Football Council, which in 1908 in Melbourne staged the first national interstate competition, the Jubilee Australasian Football Carnival, with teams representing each state and New Zealand. The game was also established early on in the new territories. In the new national capital Canberra both soccer and rugby had a head start, but following the first matches in 1911, Australian rules football in the Australian Capital Territory became a major participation sport. By 1981 it had become much neglected and quickly lagged behind the other football codes. Australian rules football in the Northern Territory began shortly after the outbreak of the war in 1916 with the first match in Darwin. The game went on to become the most popular sport in the Territory and build the highest participation rate for the sport nationally.
Both World War I and World War II had a devastating effect on Australian football and on Australian sport in general. While scratch matches were played by Australian "diggers" in remote locations around the world, the game lost many of its great players to wartime service. Some clubs and competitions never fully recovered. Between 1914 and 1915, a proposed hybrid code of Australian football and rugby league, the predominant code of football in New South Wales and Queensland, was trialled without success. In Queensland, the state league went into recess for the duration of the war. VFL club University left the league and went into recess due to severe casualties. The West Australian Football League (WAFL) lost two clubs and the SANFL was suspended for one year in 1916 due to heavy club losses. The Anzac Day match, the annual game between Essendon and Collingwood on Anzac Day, is one example of how the war continues to be remembered in the football community. The role of the Australian National Football Council (ANFC) was primarily to govern the game at a national level and to facilitate interstate representative and club competition. In 1968, the ANFC revived the Championship of Australia, a competition first held in 1888 between the premiers of the VFA and SAFA. Although clubs from other states were at times invited, the final was almost always between the premiers from the two strongest state competitions of the time—South Australia and Victoria—with Adelaide hosting most of the matches at the request of the SAFA/SANFL. The last match took place in 1976, with North Adelaide being the last non-Victorian winner in 1972. Between 1976 and 1987, the ANFC, and later the Australian Football Championships (AFC) ran a night series, which invited clubs and representative sides from around the country to participate in a knock-out tournament parallel to the premiership seasons, which Victorian sides still dominated.
With the lack of international competition, state representative matches were regarded with great importance. Due in part to the VFL poaching talent from other states, Victoria dominated interstate matches for three-quarters of a century. State of Origin rules, introduced in 1977, stipulated that rather than representing the state of their adopted club, players would return to play for the state they were first recruited in. This instantly broke Victoria's stranglehold over state titles and Western Australia and South Australia began to win more of their games against Victoria. Both New South Wales and Tasmania scored surprise victories at home against Victoria in 1990. Towards a national league. The term "Barassi Line", named after VFL star Ron Barassi, was coined by scholar Ian Turner in 1978 to describe the "fictitious geographical barrier" separating the rugby-following parts of New South Wales and Queensland from the rest of the country, where Australian football reigned. It became a reference point for the expansion of Australian football and for establishing a national league.
The way the game was played had changed dramatically due to innovative coaching tactics, with the phasing out of many of the game's kicking styles and the increasing use of handball; while presentation was influenced by television. In 1982, in a move that heralded big changes within the sport, one of the original VFL clubs, South Melbourne, relocated to Sydney and became known as the Sydney Swans. In the late 1980s, due to the poor financial standing of many of the Victorian clubs, and a similar situation existing in Western Australia in the sport, the VFL pursued a more national competition. Two more non-Victorian clubs, West Coast and Brisbane, joined the league in 1987 generating more than $8 million in license revenue for the Victorian clubs and increasing broadcast revenues which helped the Victorian clubs survive. In their early years, the Sydney and Brisbane clubs struggled both on and off-field because the substantial TV revenues they generated by playing on a Sunday went to the VFL. To protect these revenues the VFL granted significant draft concessions and financial aid to keep the expansion clubs competitive.
The VFL changed its name to the Australian Football League (AFL) for the 1990 season, and over the next decade, three non-Victorian clubs gained entry: Adelaide (1991), Fremantle (1995) and the SANFL's Port Adelaide (1997), the only pre-existing club outside Victoria to join the league. In 2011 and 2012, respectively, two new non-Victorian clubs were added to the competition: Gold Coast and Greater Western Sydney. The AFL, currently with 18 member clubs, is the sport's elite competition and most powerful body. Following the emergence of the AFL, state leagues were quickly relegated to a second-tier status. The VFA merged with the former VFL reserves competition in 1998, adopting the VFL name. State of Origin also declined in importance, especially after an increasing number of player withdrawals. The AFL turned its focus to the annual International Rules Series against Ireland in 1998 before abolishing State of Origin the following year. State and territorial leagues still contest interstate matches, as do AFL Women players.
In the 2010s, the AFL signalled further attempts at expanding into markets outside Australian football's traditional heartlands by hosting home-and-away matches in New Zealand, followed by China. After several failed bids since the early 1990s for a Tasmania-based AFL team, the Tasmania Football Club secured the 19th AFL license in 2023, and is set to compete by 2028. Laws of the game. Players and equipment. In a standard match, a team may consist of anywhere between 14 and 18 players who may be permitted on the playing surface at any given time. Each team may have up to four interchange (reserve) players who may be swapped for those on the field at any time during the game. Although some leagues in less populated areas may use as few as 12 players. In addition, some leagues notably including the AFL, have each team designate one additional player as a substitute who can be used to make a single permanent exchange of players during a game for either medical or tactical reasons. Players on the playing surface can be swapped with those on the interchange bench at any time. They must though pass through a designated "Interchange Area". In the event a player fails to pass through this area correctly, or if too many players from one team are found to be on the ground at a time, a free kick will be awarded to the opposing side.
While there is no set uniform, the basic equipment for Australian football consists of a guernsey, shorts, socks and boots, with additional pieces of apparel such as headbands and gloves additionally being permitted. Players may wear certain pieces of protective equipment, such as helmets or arm guards, if approved by the relevant controlling body. Mouthguards are strongly recommended for all players. Players are not permitted to wear jewellery, or other materials which the field umpire has deemed to be either potentially dangerous or increase the risk of injury to other players. Ball. Australian rules football is played with an ellipsoid ball, between in long circumference, and in short circumference. For women's competitions, a smaller ball size of is used. The ball must be inflated to a pressure of . There are no defined laws regarding what material a ball must be made from, but standard AFL match-used balls are produced by Sherrin using cowhide leather. While there is no standard colour of the ball, red and yellow are most common and the only colours used at AFL level. Yellow is used for games beginning after 3 pm or in an enclosed stadium, due to its greater visibility, and to assist score reviews.
Field. Unlike other forms of football which are played on rectangular fields, Australian rules football playing fields are oval-shaped, and are between long and wide. At either end of the field, two sets of posts are erected in a straight line to indicate the scoring areas on the field, each with two kinds of posts, named the goal posts and the behind posts respectively. The goal posts are placed first, located apart from each other, with a behind post being placed a further 6.4 metres to the side of each goal post. The name for the field line between two goal posts is known as the Goal Line. Around the perimeter of the field, two white lines are drawn between the set of behind posts in an arc-shape, marking the field of play. Other field markings include: The 50m arcs, centre square, centre circle and goal square are used at the beginning of each quarter or after each goal. With each team permitted a maximum of six players in each 50m arc, with one in the goal square and four players in the centre square with one in the centre circle. If this is breached, a free kick is awarded.
Match duration. A game lasts for 80 minutes, split into four-quarters consisting of 20 minutes playing time, with the clock being stopped for stoppages in play such as scores, or at the umpire's discretion, e.g. for serious injury. Leagues may choose to employ shorter quarters of play at their discretion, such as the AFLW using 17 minutes per quarter. For any given match, two timekeepers are appointed to officiate the duration. The timekeepers record all relevant statistics for the match, such as total quarter duration and score by each team. Additionally timekeepers are required to sound a siren prior to and at the conclusion of each quarter until such time they are acknowledged by the field umpires. To stop and recommence the clock, the field umpires are required to signal to the timekeepers to indicate when the clock should be stopped or restarted. Between each quarter, a break is observed to allow players a rest period. Two six-minute breaks are observed between the first and second quarters, and the third and fourth quarters. A longer 20-minute break is observed between the second and third quarter, commonly known as "half-time".
Officiation. Each game is officiated by at least five match officials, known as an umpire. These match officials are placed into three categories based upon their roles and responsibilities, with varying minimum numbers of Umpires required depending on position: At AFL level, a video score review system is utilised. Only umpires are permitted to request a review, and only scoring shots and potential scoring shots are permitted to be reviewed. Game skills. Ball movement. An Australian rules football may only be propelled forward in a select few ways as defined by the Laws of Australian Football, published by the AFL. The ball can be propelled in any direction by way of a kick or a clenched fist (called a handball)—deemed a correct disposal. Failure to dispose of the ball in one of these two methods will result in a free kick to the opposing team. If the ball is not currently in a player's possession, it can be moved legally through the usage of other means, such as punching. While in possession of the ball, players may run with the ball, but are required to either bounce or touch the ball on the ground at least once every .
Tackling. Tackling is a technique employed by players used to force opposition players to dispose of the ball when they are in possession. Failure to dispose of the ball when legally tackled may see the player penalised for 'holding the ball', except if the umpire deems there was a lack of prior opportunity to do so. The ball carrier may only be tackled between the shoulders and knees from the front or side. If the player forcefully contacts the opposing in the back while performing a tackle, the opposition player will be penalised for a push in the back. If the opposition tackles the player with possession below the knees (a "low tackle" or a "trip") or above the shoulders (a "high tackle"), the team with possession of the football gets a free kick. Furthermore, tackles deemed to be dangerous by the umpire and those conducted from front-on while an opposition player has their head over the football are deemed to be prohibited contact, and will incur a free kick against the offending player. Additionally, players may perform a technique known shepherding when the ball is within of an opposition player. Shepherding involves the use of a player's body to push, bump or otherwise block an opposition player, providing they do not have possession of the ball.
Marking. If a player takes possession of the ball that has travelled more than from another player's kick, by way of a catch within the field of play, it is deemed as a "mark". To be awarded a mark, it must be deemed that the player sufficiently controlled the ball and took possession prior to it being touched, touching the ground, or in the case of a contest, being spoiled by an opponent. Upon a mark being taken, one opposition player may choose to stand on the point on the field where the mark was taken, known as "the mark". When a mark is taken, a small protected zone is established on the field, extending either side of "the mark" and the player who marked the ball, with a small protected corridor between "the mark" and the player. The opposition player is permitted to jump, but is not allowed to move from their position on "the mark". Any other movements result in a distance penalty (50 metres in the AFL). The player who was awarded the mark may then choose to either dispose of the ball over "the mark" or may choose to attempt disposal via a different method, in which case the field umpire will call "play on"—a verbal instruction to continue play. "Play on" may also be called if the umpire deems the player awarded the mark to be taking an unreasonable amount of time to dispose of the football.
Once the player has disposed of the ball, or "play on" is called, normal play resumes. Rucking. Rucking is the only specialist skill and is performed by a ruck, the term for designated players from each side to which umpire sends the ball to commence play. Only a nominated ruck may contest ball-ups and throw-ins. They are the only player allowed within the 10 metre circle at a centre bounce. Functionally the role is analogous to a basketball center and as such rucks are typically the tallest player on the team. Lifting teammates is not allowed so the ruck may only jump to reach the ball. If the ruck does not take possession of the football, it must be tapped or fisted, which is known as a hit-out. An effective hit-out that passes the ball to a teammate is known as a hit-out to advantage. Misconduct. In the event a player breaks a rule, a free kick is awarded to the opposing team, from the location that the misconduct occurred, or the ball's current location—whichever is closer to the team's scoring zone. As when a mark is taken, this location is called "the mark", and the same protections regarding the space apply.
In the event a player engages in unsportsmanlike conduct after a free kick has been awarded or a mark has been paid to the opposing team, the umpire may instead award a 50-metre penalty. When imposed, the field umpire will advance "the mark" an additional down the field or to the goal line, whichever is closer. Additional 50-metre penalties may be awarded if the behaviour continues after the initial penalty. The laws of the game allow umpires to send off players for egregious foul play, although this law does not apply to the AFL and is largely only used at the local level. Scoring. There are two types of scoring shots in Australian football: goals and behinds. A "goal" is worth six points, and is scored when the football is propelled between the goal posts and across the goal line at any height by way of a kick from the attacking team. It may touch the ground, but must not have been touched by any player from either team or a goalpost prior to crossing the goal line. A "behind" is worth one point and is scored when:
A behind is also awarded to the team if the ball touches any part of an opposition player, including a foot, before passing across their goal or behind line. A free kick is awarded against any player who is deemed to have deliberately rushed a behind. The team that has scored the most points at the end of play wins the game. If the scores are level on points at the end of play, then the game is a draw; extra time applies only during finals matches in some competitions. As an example of a score report, consider a match between Sydney and Geelong with the former as the home team. Sydney's score of 17 goals and 5 behinds equates to 107 points. Geelong's score of 10 goals and 17 behinds equates to a 77-point tally. Sydney wins the match by a margin of 30 points. Such a result would be written as: And spoken as: Additionally, it can be said that: The home team is typically listed first and the visiting side is listed second. A draw would be written as: Governing bodies and competitions. The football season proper is from March to August (early autumn to late winter in Australia) with finals being held in September and October. In the tropics, the game is sometimes played in the wet season (October to March).
The AFL is recognised by the Australian Sports Commission as being the National Sporting Organisation for Australian football. There are also seven state/territory-based organisations in Australia, all of which are affiliated with the AFL. These state leagues hold annual semi-professional club competitions, with some also overseeing more than one league. Local semi-professional or amateur organisations and competitions are often affiliated to their state organisations. In 2002, the AFL became the "de facto" world governing body for Australian football when it pushed for the closure of the International Australian Football Council. There are also a number of affiliated organisations governing amateur clubs and competitions around the world. For almost all Australian football club competitions, the aim is to win the premiership, which is typically decided by a finals series. The teams that occupy the highest positions on the ladder after the home-and-away season play-off in a "semi-knockout" finals series, culminating in a single Grand Final match to determine the premiers. Between four and eight teams contest a finals series, typically using the AFL final eight system or a variation of the McIntyre system. The team which finishes first on the ladder after the home-and-away season is referred to as a "minor premier", but this usually holds little stand-alone significance, other than receiving a better draw in the finals.
Some metropolitan leagues have several tiered divisions, with promotion of the lower division premiers and relegation of the upper division's last placed team at the end of each year. Women and Australian football. The high level of interest shown by women in Australian football is considered unique among the world's football codes. It was the case in the 19th century, as it is in modern times, that women made up approximately half of total attendances at Australian football matches—a far greater proportion than, for example, the estimated 10 per cent of women that comprise British soccer crowds. This has been attributed in part to the egalitarian character of Australian football's early years in public parks where women could mingle freely and support the game in various ways. In terms of participation, there are occasional 19th-century references to women playing the sport, but it was not until the 1910s that the first organised women's teams and competitions appeared. Women's state leagues emerged in the 1980s, and in 2013, the AFL announced plans to establish a nationally televised women's competition. Amidst a surge in viewing interest and participation in women's football, the AFL pushed the founding date of the competition, named AFL Women's, to 2017. Eight AFL clubs won licences to field sides in its inaugural season. By the seventh season in 2022, all 18 clubs fielded a women's side.
Variations and related sports. Many related games have emerged from Australian football, mainly with variations of contact to encourage greater participation. These include Auskick (played by children aged between 5 and 12), kick-to-kick (and its variants end-to-end footy and marks up), rec footy, 9-a-side footy, masters Australian football, handball and longest-kick competitions. Players outside Australia sometimes engage in related games adapted to available fields, like metro footy (played on gridiron fields) and Samoa rules (played on rugby fields). One such prominent example in use since 2018 is AFLX, a shortened variation of the game with seven players a side, played on a soccer-sized pitch. International rules football. The similarities between Australian football and the Irish sport of Gaelic football have allowed for the creation of a hybrid code known as international rules football. The first international rules matches were contested in Ireland during the 1967 Australian Football World Tour. Since then, various sets of compromise rules have been trialed, and in 1984 the International Rules Series commenced with national representative sides selected by Australia's state leagues (later by the AFL) and the Gaelic Athletic Association (GAA). The competition became an annual event in 1998, but was postponed indefinitely in 2007 when the GAA pulled out due to Australia's severe and aggressive style of play. It resumed in Australia in 2008 under new rules to protect the player with the ball.
Global reach. During the colonial period, Australian rules was sometimes referred to as Australasian rules, reflecting its popularity in New Zealand. The game was played outside Australasia as early as 1888 when Australians studying at Edinburgh University and London University formed teams and competed in London. By the early 20th century, it had spread with the Australian diaspora to South Africa, the United States and other parts of the Anglosphere; however this growth went into rapid decline during and after World War I, leading also to a decades long hiatus in New Zealand. After World War II, it experienced growth in the Pacific region, particularly in Papua New Guinea and Nauru, where Australian football is now the national sport. Today, the sport is played at an amateur level in various countries throughout the world. Twenty-three countries have participated in the International Cup, the highest level of international competition, held triennially in Australia since 2002. Nine countries have also participated in the AFL Europe Championship with both competitions prohibiting Australian players. A fan of the sport since attending school in Victoria, King Charles is the Patron of AFL Europe. In 2013, participation across AFL Europe's 21 member nations was more than 5,000 players, the majority of which are European nationals rather than Australian expats. The sport also has a growing presence in India. Over 20 countries have either affiliation or working agreements with the AFL.
Most present-day international amateur clubs and leagues are based in North America, Europe and Asia, with the oldest typically having originated in the 1980s. That decade, the sport developed a cult following in the United States when matches were broadcast on the fledgling ESPN network. Growing international interest has been assisted by exhibition matches, players switching between football codes, and Australia's multicultural makeup. Many VFL/AFL players were born overseas, with a growing number recruited through various initiatives. One notable example is the Irish experiment, which, since the 1980s, has seen many Gaelic footballers leave the amateur GAA to play Australian rules professionally. This has expanded to the AFLW, where it has grown from one Irish player in the debut 2017 season, to 36 in 2024. Although Australian rules football is not an Olympic sport, it was showcased at the MCG as part of the 1956 Summer Olympics, held in Melbourne. In addition, when Brisbane hosted the 1982 Commonwealth Games, an exhibition match was held at the Gabba.
Cultural influence and popularity. Australian football has attracted more overall interest among Australians than any other football code, and, when compared with all sports throughout the nation, has consistently ranked first in the winter reports, and third behind cricket and swimming in summer. Over 1,057,572 fans were paying members of AFL clubs in 2019. The 2021 AFL Grand Final was the year's most-watched television broadcast in Australia, with an in-home audience of up to 4.11 million. In 2019, there were 1,716,276 registered participants in Australia including 586,422 females (34 per cent of the overall total) and more than 177,000 registered outside Australia including 79,000 females (45 per cent of the overall total). In the arts and popular culture. Australian football has inspired works by many writers and poets, including C. J. Dennis, Helen Garner, Peter Goldsworthy and Kerry Greenwood. Historians Manning Clarke and Geoffrey Blainey have also written extensively on the sport. Slang within Australian football has impacted Australian English more broadly, with a number of expressions taking on new meanings in non-sporting contexts, e.g., to "get a guernsey" is to gain recognition or approval, while "shirt-fronting" someone is to accost them.
In 1889, Australian impressionist painter Arthur Streeton captured football games "en plein air" for the 9 by 5 Impression Exhibition, titling one work "The National Game". Paintings by Sidney Nolan ("Footballer", 1946) and John Brack ("Three of the Players", 1953) helped to establish Australian football as a serious subject for modernists, and many Aboriginal artists have explored the game, often fusing it with the mythology of their region. Vincent Namatjira won the 2020 Archibald Prize for his portrait of Adam Goodes. In cartooning, WEG's VFL/AFL premiership posters—inaugurated in 1954—have achieved iconic status among Australian football fans. Australian football statues can be found throughout the country, some based on famous photographs, among them Haydn Bunton Sr.'s leap, Jack Dyer's charge and Nicky Winmar lifting his jumper. In the 1980s, a group of postmodern architects based in Melbourne began incorporating references to Australian football into their buildings, an example being Building 8 by Edmond and Corrigan.
Dance sequences based on Australian football feature heavily in Robert Helpmann's 1964 ballet "The Display", his first and most famous work for the Australian Ballet. The game has also inspired well-known plays such as "And the Big Men Fly" (1963) by Alan Hopgood and David Williamson's "The Club" (1977), which was adapted into a 1980 film, directed by Bruce Beresford. Mike Brady's 1979 hit "Up There Cazaly" is considered an Australian football anthem, and references to the sport can be found in works by popular musicians, from singer-songwriter Paul Kelly to the alternative rock band TISM. Others, such as Tame Impala's Kevin Parker, have written songs for their favourite AFL club. Many Australian football video games have been released, notably the AFL series. Australian Football Hall of Fame. For the centenary of the VFL/AFL in 1996, the Australian Football Hall of Fame was established. That year, 136 significant figures across the various competitions were inducted into the Hall of Fame. Each years since the creation of the Hall of Fame, a panel selects a small group of players they deem worthy for this prestigious honour, resulting in a total number of more than 300 inductees as of 2024. In addition to the Hall of Fame, select members are chosen to receive the elite "Legend" status. Due to restrictions limiting the number of Legend status players to 10% of the total number of Hall of Fame inductees, there are currently only 32 players with the status in the Hall of Fame as of 2024.
Aon (company) Aon plc () is a British-American professional services firm that offers a range of risk-mitigation products. Aon has over 66,000 employees across 120 countries. Founded in Chicago by Patrick Ryan, Aon was created in 1982 when the Ryan Insurance Group merged with the Combined Insurance Company of America under W. Clement Stone. In 1987, the holding company was renamed Aon from "aon", a Gaelic word meaning "one". The company is globally headquartered in London with its North America operations based in Chicago at the Aon Center. Aon is listed on the New York Stock Exchange under AON with a market cap of $65 billion in April 2023. History. W. Clement Stone's mother bought a small Detroit insurance agency, and in 1918 brought her son into the business. Mr. Stone sold low-cost, low-benefit accident insurance, underwriting and issuing policies on-site. The next year he founded his own agency, the Combined Registry Co. As the Great Depression began, Stone reduced his workforce and improved training. Forced by his son's respiratory illness to winter in the South, Stone moved to Arkansas and Texas. In 1939 he bought American Casualty Insurance Co. of Dallas, Texas. It was consolidated with other purchases as the Combined Insurance Co. of America in 1947. The company continued through the 1950s and 1960s, continuing to sell health and accident policies. In the 1970s, Combined expanded overseas despite being hit hard by the recession.
In 1982, after 10 years of stagnation under Clement Stone Jr., the elder Stone, then 79, resumed control until the completion of a merger with Ryan Insurance Co. allowed him to transfer control to Patrick Ryan. Ryan, the son of a Ford dealer in Wisconsin and a graduate of Northwestern University, had started his company as an auto credit insurer in 1964. In 1976, the company bought the insurance brokerage units of the Esmark conglomerate. Ryan focused on insurance brokering and added more upscale insurance products. He also trimmed staff and took other cost-cutting measures, and in 1987 he changed Combined's name to Aon. In 1992, he bought Dutch insurance broker Hudig-Langeveldt. In 1995, the company sold its remaining direct life insurance holdings to General Electric to focus on consulting. Aon built a global presence through purchases. In 1997, it bought The Minet Group, as well as insurance brokerage Alexander & Alexander Services, Inc. in a deal that made Aon (temporarily) the largest insurance broker worldwide. The firm made no US buys in 1998, but doubled its employee base with purchases including Spain's largest retail insurance broker, Gil y Carvajal, and the formation of Aon Korea.
Responding to industry demands, Aon announced its new fee disclosure policy in 1999, and the company reorganised to focus on buying personal line insurance firms and to integrate its acquisitions. That year it bought Nikols Sedgwick Group, an Italian insurance firm, and formed RiskAttack (with Zurich US), a risk analysis and financial management concern aimed at technology companies. The cost of integrating its numerous purchases, however, hammered profits in 1999. Despite its troubles, in 2000 Aon bought Reliance Group's accident and health insurance business, as well as Actuarial Sciences Associates, a compensation and employee benefits consulting company. Later in that year, however, the company decided to cut 6% of its workforce as part of a restructuring effort. In 2003, the company saw revenues increase primarily because of rate hikes in the insurance industry. Also that year, Endurance Specialty, a Bermuda-based underwriting operation that Aon helped to establish in November 2001 along with other investors, went public. The next year Aon sold most of its holdings in Endurance.
In the late 2007, Aon announced the divestiture of its underwriting business. With this move, the firm sold off its two major underwriting subsidiaries: Combined Insurance Company of America (acquired by ACE Limited for $2.4 billion) and Sterling Life Insurance Company (purchased by Munich Re Group for $352 million). The low margin and capital-intensive nature of the underwriting industry was the primary reason for the firm's decision to divest. This growth strategy manifested in November 2008 when Aon announced it had acquired reinsurance intermediary and capital advisor Benfield Group Limited for $1.75 billion. The acquisition amplified the firm's broking capabilities, positioning Aon one of the largest players in the reinsurance brokerage industry. In 2010, Aon made its most significant acquisition to date with the purchase of Hewitt Associates for $4.9 billion. Aside from drastically boosting Aon's human resources consulting capacity and entering the firm into the business process outsourcing industry, the move added 23,000 colleagues and more than $3 billion in revenue.
In January 2012, Aon announced that its headquarters would be moved to London, although North American operations and jobs remained in Chicago. On 10 February 2017, Aon announced that it was selling its employee benefits outsourcing business to private equity firm The Blackstone Group for US$4.8 billion (£3.8 billion). In February 2020, Aon named Eric Andersen as president of Aon after co-president Michael O'Connor departed the company to pursue new opportunities. He will be reporting to Greg Case, the firm's CEO. In June 2020, Aon announced it was planning to repay the temporary 20% pay cut from 70% of employees that was published in a statement in April 2020 regarding the COVID-19 pandemic. On 30 June 2020, Aon announced it would repay staff in full, plus 5% of the withheld amount. In June 2020, Willis Towers Watson called its shareholders to two meetings to discuss its acquisition with Aon for August 26, 2020. It was revealed that the US Department of Justice has requested more information on the deal under antitrust rules.
September 11 attacks. Aon's New York offices were on the 92nd and 98th–105th floors of the South Tower of the World Trade Center at the time of the September 11 attacks. When the North Tower was struck by American Airlines Flight 11 at 8:46 a.m., an evacuation of Aon's offices was quickly initiated by executive Eric Eisenberg, and 924 of the estimated 1,100 Aon employees present at the time managed to get below the 77th floor before United Airlines Flight 175 crashed between Floors 77 and 85 at 9:03 a.m. Many, however, did not manage to get beneath in the 17 minutes they had between the two impacts. As a result, 176 employees of Aon were killed in the crash or died in the eventual collapse of the tower or from smoke inhalation. At 9:59 a.m., the tower collapsed, killing any survivors still within, including Eisenberg and Kevin Cosgrove. Spitzer investigation. In 2004–2005, Aon, along with other brokers including Marsh & McLennan and Willis, fell under regulatory investigation under New York Attorney General Eliot Spitzer and other state attorneys general. At issue was the practice of insurance companies' payments to brokers (known as contingent commissions). The payments were thought to bring a conflict of interest, swaying broker decisions on behalf of carriers, rather than customers. In the spring of 2005, without acknowledging any wrongdoing, Aon agreed to a $190 million settlement, payable over 30 months.
UK regulatory breach. In January 2009, Aon was fined £5.69 million in the UK by the Financial Services Authority, who stated that the fine related to the company's inadequate bribery and corruption controls, claiming that between 14 January 2005 and 30 September 2007 Aon had failed to properly assess the risks involved in its dealings with overseas firms and individuals. The Authority did not find that any money had actually made its way to illegal organisations. Aon qualified for a 30% discount on the fine as a result of its cooperation with the investigation. Aon said its conduct was not deliberate, adding it had since "significantly strengthened and enhanced its controls around the usage of third parties". US Foreign Corrupt Practices Act violations. In December 2011, Aon Corporation paid a $16.26 million penalty to the U.S. Securities and Exchange Commission and the U.S. Department of Justice for violations of the US Foreign Corrupt Practices Act. According to the Securities and Exchange Commission, Aon's subsidiaries made improper payments of over $3.6 million to government officials and third-party facilitators in Costa Rica, Egypt, Vietnam, Indonesia, the United Arab Emirates, Myanmar and Bangladesh, between 1983 and 2007, to obtain and retain insurance contracts.
Major acquisitions. On 5 January 2007, Aon announced that its Aon Affinity group had acquired the WedSafe Wedding Insurance program. On 22 August 2008, Aon announced that it had acquired London-based Benfield Group. The acquiring price was US$1.75 billion or £935 million, with US$170 million of debt. On 5 March 2010, Hewitt Associates announced that it acquired Senior Educators Ltd. The acquisition offers companies a new way to address retiree medical insurance commitments. On 12 July 2010, Aon announced that it had agreed to buy Lincolnshire, Illinois-based Hewitt Associates for $4.9 billion in cash and stock. On 7 April 2011, Aon announced that it had acquired Johannesburg, South Africa-based Glenrand MIB. Financial terms were not disclosed. On 19 July 2011, Aon announced that it bought Westfield Financial Corp., the owner of insurance-industry consulting firm Ward Financial Group, from Ohio Farmers Insurance Co. Financial terms were not disclosed. On 22 October 2012, Aon announced that it agreed to buy OmniPoint, Inc, a Workday consulting firm. Financial terms were not disclosed.
On 16 June 2014, Aon announced that it agreed to buy National Flood Services, Inc., a large processor of flood insurance, from Stoneriver Group, L.P. On 31 October 2016, Aon's Aon Risk Solutions completed acquisition of Stroz Friedberg LLC, a specialised risk management firm focusing on cybersecurity. On 14 November 2016, Aon acquired CoCubes an online Indian Assessment firm, facilitating hiring of entry-level engineering graduates. On 10 February 2017, Aon plc agreed to sell its human resources outsourcing platform for US$4.8 billion (£3.8 billion) to Blackstone Group L.P. (BX.N), creating a new company called Alight Solutions. In September 2017, Aon announced its intent to purchase real estate investment management firm The Townsend Group from Colony NorthStar for $475 million, expanding Aon's property investment management portfolio. On 9 March 2020, Aon announced its merger with Willis Towers Watson for nearly $30 billion in an all-stock deal that creates the world's largest insurance broker. As of 21 May 2020, Willis board was under probe over merger agreement with Aon. The deal was called off in July 2021.
In December 2023, Aon agreed to acquire NFP, a middle-market provider of risk, benefits, wealth and retirement plan advisory services company, for $13.4 billion. In March 2024, Aon plc acquired the technology assets and intellectual property of Humn.ai, an AI-powered platform. This will enhance its commercial fleet proposition. Operations. Manchester United. On 3 June 2009, it was reported that Aon had signed a four-year shirt sponsorship deal with English football giant Manchester United. On 1 June 2010, Aon replaced American insurance company AIG as the principal sponsor of the club. The Aon logo was prominently displayed on the front of the club's shirts until the 2014/2015 season when Chevrolet replaced them. The deal was said to be worth £80 million over four years, replacing United's deal with AIG as the most lucrative shirt deal in history at the time. In April 2013, Aon signed a new eight-year deal with Manchester United to rename their training ground as the Aon Training Complex and sponsor the club's training kits, reportedly worth £180 million to the club.
Alban Berg Alban Maria Johannes Berg ( , ; 9 February 1885 – 24 December 1935) was an Austrian composer of the Second Viennese School. His compositional style combined Romantic lyricism with the twelve-tone technique. Although he left a relatively small "oeuvre", he is remembered as one of the most important composers of the 20th century for his expressive style encompassing "entire worlds of emotion and structure". Berg was born and lived in Vienna. He began to compose at the age of fifteen. He studied counterpoint, music theory and harmony with Arnold Schoenberg between 1904 and 1911, and adopted his principles of "developing variation" and the twelve-tone technique. Berg's major works include the operas "Wozzeck" (1924) and "Lulu" (1935, finished posthumously), the chamber pieces "Lyric Suite" and Chamber Concerto, as well as a Violin Concerto. He also composed a number of songs ("lieder"). He is said to have brought more "human values" to the twelve-tone system; his works are seen as more "emotional" than those of Schoenberg. His music had a surface glamour that won him admirers when Schoenberg himself had few.
Berg died from sepsis in 1935. Life and career. Early life. Berg was born in Vienna, the third of four children of Johanna and Konrad Berg. His father ran a successful export business, and the family owned several estates in Vienna and the countryside. The family's financial situation turned to the worse after the death of Konrad Berg in 1900, and it particularly affected young Berg, who had to repeat both his sixth and seventh grade to pass the exams. One of his closest lifelong friends and earliest biographer (under the pseudonym Hermann Herrenried), architect Hermann Watznauer, became a father figure (partly at Konrad's request), being ten years Berg's senior. Berg wrote him letters as long as thirty pages, often in florid, dramatic prose with idiosyncratic punctuation. Berg was more interested in literature than music as a child and would consider a career as a writer several times, turning to music slowly and at times unconfidently until the success of "Wozzeck". He did not begin to compose until he was fifteen, when he started to teach himself music, although he did take piano lessons from his sister's governess. With Marie Scheuchl, a maid in the family estate of Berghof in Carinthia and fifteen years his senior, he fathered a daughter, Albine, born 4 December 1902.
In 1906 Berg met the singer (1885–1976), daughter of a wealthy family (rumoured to be in fact the illegitimate daughter of Emperor Franz Joseph I from his liaison with Anna Nahowski). Despite the outward hostility of her family, the couple married on 3 May 1911, although "her father insisted on a Protestant ceremony to facilitate the divorce he foresaw as inevitable." Early works (1907–1914). With little prior music education, Berg began studying counterpoint, music theory, and harmony under Arnold Schoenberg in October 1904. By 1906 he was studying music full-time; by 1907 he began composition lessons. His student compositions included five drafts for piano sonatas. He also wrote songs, including his "Seven Early Songs" ("Sieben frühe Lieder"), three of which were Berg's first publicly performed work in a concert that featured the music of Schoenberg's pupils in Vienna that year. The early sketches eventually culminated in the Piano Sonata, Op. 1, published in 1910 and likely composed 19081909; it has been described as one of the most formidable "first" works ever written. Berg studied with Schoenberg for six years until 1911. Among Schoenberg's teachings was the idea that the unity of a musical composition depends upon all its aspects being derived from a single basic idea; this idea was later known as "developing variation". Berg passed this on to his students, one of whom, Theodor W. Adorno, stated: "The main principle he conveyed was that of variation: everything was supposed to develop out of something else and yet be intrinsically different". The Piano Sonata is an example—the whole composition is derived from the work's opening quartal gesture and its opening phrase.
Berg was a part of Vienna's cultural elite during the heady "fin de siècle" period. His circle included the musicians Alexander von Zemlinsky and Franz Schreker, the painter Gustav Klimt, the writer and satirist Karl Kraus, the architect Adolf Loos, and the poet Peter Altenberg. In 1913 two of Berg's "Altenberg Lieder" (1912) premiered in Vienna, conducted by Schoenberg in the infamous "Skandalkonzert". Settings of aphoristic poetic utterances, the songs are accompanied by a very large orchestra. The performance caused a riot, and had to be halted. Berg effectively withdrew the work, and it was not performed in full until 1952. The full score remained unpublished until 1966. Berg had a particular interest in the number 23, using it to structure several works. Various suggestions have been made as to the reason for this interest: that he took it from the biorhythms theory of Wilhelm Fliess, in which a 23-day cycle is considered significant, or because he first suffered an asthma attack on the 23rd of the month.
"Wozzeck" (1917–1924) and "Lulu" (1928–1929). From 1915 to 1918 Berg served in the Austro-Hungarian Army. During a period of leave in 1917 he accelerated work on his first opera, "Wozzeck". After the end of World War I, he settled again in Vienna, where he taught private pupils. He also helped Schoenberg run his Society for Private Musical Performances, which sought to create the ideal environment for the exploration and appreciation of unfamiliar new music by means of open rehearsals, repeat performances, and the exclusion of professional critics. In 1924 three excerpts from "Wozzeck" were performed, which brought Berg his first public success. The opera, which Berg completed in 1922, was first performed on 14 December 1925, when Erich Kleiber conducted the first performance in Berlin. Today, "Wozzeck" is seen as one of the century's most important works. Berg made a start on his second opera, the three-act "Lulu", in 1928 but interrupted the work in 1929 for the concert aria "Der Wein" which he completed that summer. "Der Wein" presaged "Lulu" in a number of ways, including vocal style, orchestration, design and text.
Other well-known Berg compositions include the "Lyric Suite" (1926), which was later shown to employ elaborate cyphers to document a secret love affair; the post-Mahlerian Three Pieces for Orchestra (completed in 1915 but not performed until after "Wozzeck"); and the Chamber Concerto ("Kammerkonzert", 1923–25) for violin, piano, and 13 wind instruments: this latter is written so conscientiously that Pierre Boulez has called it "Berg's strictest composition" and it, too, is permeated by cyphers and posthumously disclosed hidden programs. It was at this time he began exhibiting tone clusters in his works after meeting with American avant-garde composer Henry Cowell, with whom he would eventually form a lifelong friendship. Final years (1930–1935). Life for the musical world was becoming increasingly difficult in the 1930s both in Vienna and Germany due to the rising tide of antisemitism and the Nazi cultural ideology that denounced modernity. Even to have an association with someone who was Jewish could lead to denunciation, and Berg's "crime" was to have studied with the Jewish composer Arnold Schoenberg. Berg found that opportunities for his work to be performed in Germany were becoming rare, and eventually his music was proscribed and placed on the list of degenerate music.
In 1932 Berg and his wife acquired an isolated lodge, the "Waldhaus" on the southern shore of the Wörthersee, near Schiefling am See in Carinthia, where he was able to work in seclusion, mainly on "Lulu" and the Violin Concerto. At the end of 1934, Berg became involved in the political intrigues around finding a replacement for Clemens Krauss as director of the Vienna State Opera. As more of the performances of his work in Germany were cancelled by the Nazis, who had come to power in early 1933, he needed to ensure the new director would be an advocate for modernist music. Originally, the premiere of "Lulu" had been planned for the Berlin State Opera, where Erich Kleiber continued to champion his music and had conducted the premiere of "Wozzeck" in 1925, but now this was looking increasingly uncertain, and "Lulu" was rejected by the Berlin authorities in the spring of 1934. Kleiber's production of the "Lulu" symphonic suite on 30 November 1934 in Berlin was also the occasion of his resignation in protest at the extent of conflation of culture with politics. Even in Vienna, the opportunities for the Vienna School of musicians were dwindling.
Berg had interrupted the orchestration of "Lulu" because of an unexpected (and financially much-needed) commission from the Russian-American violinist Louis Krasner for a Violin Concerto (1935). This profoundly elegiac work, composed at unaccustomed speed and posthumously premiered, has become one of Berg's frequently performed compositions. Like much of his mature work, it employs an idiosyncratic adaptation of Schoenberg's "dodecaphonic" or twelve-tone technique, that enables the composer to produce passages openly evoking tonality, including quotations from historical tonal music, such as a Bach chorale and a Carinthian folk song. The Violin Concerto was dedicated "to the memory of an Angel", Manon Gropius, the deceased daughter of architect Walter Gropius and Alma Mahler. Death. Berg died aged 50 in Vienna, on Christmas Eve 1935, from blood poisoning apparently caused by a furuncle on his back, induced by an insect sting that occurred in November. He was buried at the Hietzing Cemetery in Vienna. Before he died, Berg had completed the orchestration of only the first two of the three acts of "Lulu". The completed acts were successfully premièred in Zürich in 1937. For personal reasons Helene Berg subsequently imposed a ban on any attempt to "complete" the final act, which Berg had in fact completed in short score. An orchestration was therefore commissioned in secret from Friedrich Cerha and premièred in Paris (under Pierre Boulez) only in 1979, soon after Helene Berg's own death.
Legacy. Berg is remembered as one of the most important composers of the 20th century and the most widely performed opera composer among the Second Viennese School. He is said to have brought more "human values" to the twelve-tone system, his works seen as more "emotional" than Schoenberg's. Critically, he is seen as having preserved the Viennese tradition in his music. Berg scholar Douglas Jarman writes in "The New Grove Dictionary of Music and Musicians" that "[as] the 20th century closed, the 'backward-looking' Berg suddenly came as [George] Perle remarked, to look like its most forward-looking composer." The Alban Berg Foundation, founded by the composer's widow in 1969, cultivates the memory and works of the composer, and awards scholarships. The Alban Berg Monument, situated next to the Vienna State Opera and unveiled in 2016, was funded by the Foundation. The Alban Berg Quartett was a string quartet named after him, active from 1971 until 2008. The asteroid 4528 Berg is named after him (1983). Major compositions. Piano Orchestral Vocal Operas
Analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern analytical techniques. Classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, solubility, radioactivity or reactivity. Classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation. Then qualitative and quantitative analysis can be performed, often with the same instrument and may use light interaction, heat interaction, electric fields or magnetic fields. Often the same instrument can separate, identify and quantify an analyte.
Analytical chemistry is also focused on improvements in experimental design, chemometrics, and the creation of new measurement tools. Analytical chemistry has broad applications to medicine, science, and engineering. History. Analytical chemistry has been important since the early days of chemistry, providing methods for determining which elements and chemicals are present in the object in question. During this period, significant contributions to analytical chemistry included the development of systematic elemental analysis by Justus von Liebig and systematized organic analysis based on the specific reactions of functional groups. The first instrumental analysis was flame emissive spectrometry developed by Robert Bunsen and Gustav Kirchhoff who discovered rubidium (Rb) and caesium (Cs) in 1860. Most of the major developments in analytical chemistry took place after 1900. During this period, instrumental analysis became progressively dominant in the field. In particular, many of the basic spectroscopic and spectrometric techniques were discovered in the early 20th century and refined in the late 20th century.
The separation sciences follow a similar time line of development and also became increasingly transformed into high performance instruments. In the 1970s many of these techniques began to be used together as hybrid techniques to achieve a complete characterization of samples. Starting in the 1970s, analytical chemistry became progressively more inclusive of biological questions (bioanalytical chemistry), whereas it had previously been largely focused on inorganic or small organic molecules. Lasers have been increasingly used as probes and even to initiate and influence a wide variety of reactions. The late 20th century also saw an expansion of the application of analytical chemistry from somewhat academic chemical questions to forensic, environmental, industrial and medical questions, such as in histology. Modern analytical chemistry is dominated by instrumental analysis. Many analytical chemists focus on a single type of instrument. Academics tend to either focus on new applications and discoveries or on new methods of analysis. The discovery of a chemical present in blood that increases the risk of cancer would be a discovery that an analytical chemist might be involved in. An effort to develop a new method might involve the use of a tunable laser to increase the specificity and sensitivity of a spectrometric method. Many methods, once developed, are kept purposely static so that data can be compared over long periods of time. This is particularly true in industrial quality assurance (QA), forensic and environmental applications. Analytical chemistry plays an increasingly important role in the pharmaceutical industry where, aside from QA, it is used in the discovery of new drug candidates and in clinical applications where understanding the interactions between the drug and the patient are critical.
Classical methods. Although modern analytical chemistry is dominated by sophisticated instrumentation, the roots of analytical chemistry and some of the principles used in modern instruments are from traditional techniques, many of which are still used today. These techniques also tend to form the backbone of most undergraduate analytical chemistry educational labs. Qualitative analysis. Qualitative analysis determines the presence or absence of a particular compound, but not the mass or concentration. By definition, qualitative analyses do not measure quantity. Chemical tests. There are numerous qualitative chemical tests, for example, the acid test for gold and the Kastle-Meyer test for the presence of blood. Flame test. Inorganic qualitative analysis generally refers to a systematic scheme to confirm the presence of certain aqueous ions or elements by performing a series of reactions that eliminate a range of possibilities and then confirm suspected ions with a confirming test. Sometimes small carbon-containing ions are included in such schemes. With modern instrumentation, these tests are rarely used but can be useful for educational purposes and in fieldwork or other situations where access to state-of-the-art instruments is not available or expedient.
Quantitative analysis. Quantitative analysis is the measurement of the quantities of particular chemical constituents present in a substance. Quantities can be measured by mass (gravimetric analysis) or volume (volumetric analysis). Gravimetric analysis. The gravimetric analysis involves determining the amount of material present by weighing the sample before and/or after some transformation. A common example used in undergraduate education is the determination of the amount of water in a hydrate by heating the sample to remove the water such that the difference in weight is due to the loss of water. Volumetric analysis. Titration involves the gradual addition of a measurable reactant to an exact volume of a solution being analyzed until some equivalence point is reached. Titration is a family of techniques used to determine the concentration of an analyte. Titrating accurately to either the half-equivalence point or the endpoint of a titration allows the chemist to determine the amount of moles used, which can then be used to determine a concentration or composition of the titrant. Most familiar to those who have taken chemistry during secondary education is the acid-base titration involving a color-changing indicator, such as phenolphthalein. There are many other types of titrations, for example, potentiometric titrations or precipitation titrations. Chemists might also create titration curves in order by systematically testing the pH every drop in order to understand different properties of the titrant.
Instrumental methods. Spectroscopy. Spectroscopy measures the interaction of the molecules with electromagnetic radiation. Spectroscopy consists of many different applications such as atomic absorption spectroscopy, atomic emission spectroscopy, ultraviolet-visible spectroscopy, X-ray spectroscopy, fluorescence spectroscopy, infrared spectroscopy, Raman spectroscopy, dual polarization interferometry, nuclear magnetic resonance spectroscopy, photoemission spectroscopy, Mössbauer spectroscopy and so on. Mass spectrometry. Mass spectrometry measures mass-to-charge ratio of molecules using electric and magnetic fields. In a mass spectrometer, a small amount of sample is ionized and converted to gaseous ions, where they are separated and analyzed according to their mass-to-charge ratios. There are several ionization methods: electron ionization, chemical ionization, electrospray ionization, fast atom bombardment, matrix-assisted laser desorption/ionization, and others. Also, mass spectrometry is categorized by approaches of mass analyzers: magnetic-sector, quadrupole mass analyzer, quadrupole ion trap, time-of-flight, Fourier transform ion cyclotron resonance, and so on.
Electrochemical analysis. Electroanalytical methods measure the potential (volts) and/or current (amps) in an electrochemical cell containing the analyte. These methods can be categorized according to which aspects of the cell are controlled and which are measured. The four main categories are potentiometry (the difference in electrode potentials is measured), coulometry (the transferred charge is measured over time), amperometry (the cell's current is measured over time), and voltammetry (the cell's current is measured while actively altering the cell's potential). Potentiometry measures the cell's potential, coulometry measures the cell's current, and voltammetry measures the change in current when cell potential changes. Thermal analysis. Calorimetry and thermogravimetric analysis measure the interaction of a material and heat. Separation. Separation processes are used to decrease the complexity of material mixtures. Chromatography, electrophoresis and field flow fractionation are representative of this field.
Chromatographic assays. Chromatography can be used to determine the presence of substances in a sample as different components in a mixture have different tendencies to adsorb onto the stationary phase or dissolve in the mobile phase. Thus, different components of the mixture move at different speed. Different components of a mixture can therefore be identified by their respective R"ƒ" values, which is the ratio between the migration distance of the substance and the migration distance of the solvent front during chromatography. In combination with the instrumental methods, chromatography can be used in quantitative determination of the substances. Chromatography separates the analyte from the rest of the sample so that it may be measured without interference from other compounds. There are different types of chromatography that differ from the media they use to separate the analyte and the sample. In Thin-layer chromatography, the analyte mixture moves up and separates along the coated sheet under the volatile mobile phase. In Gas chromatography, gas separates the volatile analytes. A common method for chromatography using liquid as a mobile phase is High-performance liquid chromatography.
Hybrid techniques. Combinations of the above techniques produce a "hybrid" or "hyphenated" technique. Several examples are in popular use today and new hybrid techniques are under development. For example, gas chromatography-mass spectrometry, gas chromatography-infrared spectroscopy, liquid chromatography-mass spectrometry, liquid chromatography-NMR spectroscopy, liquid chromatography-infrared spectroscopy, and capillary electrophoresis-mass spectrometry. Hyphenated separation techniques refer to a combination of two (or more) techniques to detect and separate chemicals from solutions. Most often the other technique is some form of chromatography. Hyphenated techniques are widely used in chemistry and biochemistry. A slash is sometimes used instead of hyphen, especially if the name of one of the methods contains a hyphen itself. Microscopy. The visualization of single molecules, single cells, biological tissues, and nanomaterials is an important and attractive approach in analytical science. Also, hybridization with other traditional analytical tools is revolutionizing analytical science. Microscopy can be categorized into three different fields: optical microscopy, electron microscopy, and scanning probe microscopy. Recently, this field is rapidly progressing because of the rapid development of the computer and camera industries.
Lab-on-a-chip. Devices that integrate (multiple) laboratory functions on a single chip of only millimeters to a few square centimeters in size and that are capable of handling extremely small fluid volumes down to less than picoliters. Errors. Error can be defined as numerical difference between observed value and true value. The experimental error can be divided into two types, systematic error and random error. Systematic error results from a flaw in equipment or the design of an experiment while random error results from uncontrolled or uncontrollable variables in the experiment. In error the true value and observed value in chemical analysis can be related with each other by the equation where An error of a measurement is an inverse measure of accurate measurement, i.e. smaller the error greater the accuracy of the measurement. Errors can be expressed relatively. Given the relative error(formula_5): The percent error can also be calculated: If we want to use these values in a function, we may also want to calculate the error of the function. Let formula_8 be a function with formula_9 variables. Therefore, the propagation of uncertainty must be calculated in order to know the error in formula_8:
Standards. Standard curve. A general method for analysis of concentration involves the creation of a calibration curve. This allows for the determination of the amount of a chemical in a material by comparing the results of an unknown sample to those of a series of known standards. If the concentration of element or compound in a sample is too high for the detection range of the technique, it can simply be diluted in a pure solvent. If the amount in the sample is below an instrument's range of measurement, the method of addition can be used. In this method, a known quantity of the element or compound under study is added, and the difference between the concentration added and the concentration observed is the amount actually in the sample. Internal standards. Sometimes an internal standard is added at a known concentration directly to an analytical sample to aid in quantitation. The amount of analyte present is then determined relative to the internal standard as a calibrant. An ideal internal standard is an isotopically enriched analyte which gives rise to the method of isotope dilution.
Standard addition. The method of standard addition is used in instrumental analysis to determine the concentration of a substance (analyte) in an unknown sample by comparison to a set of samples of known concentration, similar to using a calibration curve. Standard addition can be applied to most analytical techniques and is used instead of a calibration curve to solve the matrix effect problem. Signals and noise. One of the most important components of analytical chemistry is maximizing the desired signal while minimizing the associated noise. The analytical figure of merit is known as the signal-to-noise ratio (S/N or SNR). Noise can arise from environmental factors as well as from fundamental physical processes. Thermal noise. Thermal noise results from the motion of charge carriers (usually electrons) in an electrical circuit generated by their thermal motion. Thermal noise is white noise meaning that the power spectral density is constant throughout the frequency spectrum. The root mean square value of the thermal noise in a resistor is given by

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