Bayer AG traces its origins to a modest dyestuffs workshop in Barmen, Germany (now part of Wuppertal), where Friedrich Bayer, a dye salesman, and Johann Friedrich Weskott, a master dyer, established Farbenfabriken vorm. Friedr. Bayer & Comp. on August 1, 1863. The company initially produced synthetic fuchsine and aniline dyes, leveraging the emerging field of coal-tar chemistry that was transforming the textile industry. Friedrich Bayer's son, also named Friedrich (1851-1920), joined the company in 1873 as a chemist and became the driving force behind its scientific expansion. After the elder Friedrich's death in 1880, the company was converted into a joint-stock corporation, Farbenfabriken vorm. Friedr. Bayer & Co., and began diversifying beyond dyestuffs into pharmaceuticals and agricultural chemicals. The pivotal moment in Bayer's early history came in 1897 when chemist Felix Hoffmann synthesized acetylsalicylic acid in a stable, pure form suitable for medicinal use. Hoffmann was seeking a treatment for his father's rheumatism that would not cause the severe stomach irritation associated with salicylic acid. On March 6, 1899, Bayer registered the trademark 'Aspirin' for its acetylsalicylic acid product, and by 1900 the drug was being sold worldwide. Aspirin became the world's first mass-market synthetic drug and remains one of the most widely consumed medications in history, with over 10 billion tablets taken annually. The Bayer Cross logo, introduced in 1904 and stamped on every aspirin tablet from 1910, became one of the most recognizable corporate symbols globally. Bayer's early pharmaceutical portfolio also included less fortunate products. In 1898, the company began marketing heroin (diacetylmorphine) as a non-addictive cough suppressant and treatment for tuberculosis and pneumonia. The drug was a Bayer trademark until after World War I, when its addictive properties became widely recognized. In 1903, Bayer licensed diethylbarbituric acid from Emil Fischer and Joseph von Mering, marketing it as Veronal, the first barbiturate sleep aid. Systematic research at Bayer led to the discovery of phenobarbital in 1911, which became a mainstay of epilepsy treatment and remains on the WHO List of Essential Medicines. The company's scientific reputation was further established in 1932 when Gerhard Domagk, leading a research team at Bayer Laboratories, developed Prontosil—the first sulfonamide antibacterial and forerunner of modern antibiotics. Domagk received the Nobel Prize in Physiology or Medicine in 1939 for this discovery. World War I brought severe disruption. Bayer's U.S. assets and trademarks, including the Aspirin trademark, were confiscated by the Alien Property Custodian and sold to Sterling Products in 1918. The company lost its American market for decades and was forced to rebuild its international presence from scratch. In 1925, Bayer merged with BASF, Hoechst, Agfa, and other German chemical companies to form IG Farbenindustrie AG (IG Farben), creating the world's largest chemical and pharmaceutical conglomerate. IG Farben's role in the Nazi war effort, including the production of Zyklon B gas used in concentration camps, the use of slave labor from Auschwitz, and human medical experimentation, led to the seizure of its assets by the Allied Control Council after World War II. In 1951, IG Farben was dissolved and its constituent companies were re-established as independent entities. Bayer was reincorporated as Farbenfabriken Bayer AG and quickly regained its position as a leading global chemical and pharmaceutical company during West Germany's Wirtschaftswonder (economic miracle). The post-war period saw controversial hiring decisions: several former Nazis, including Fritz ter Meer—convicted at the IG Farben Trial for crimes against humanity and slavery—were rehired to senior positions after brief incarceration. The company's expansion continued through the second half of the 20th century. In 1994, Bayer purchased Sterling Winthrop's over-the-counter drug business from SmithKline Beecham, reclaiming the U.S. and Canadian trademark rights to 'Bayer' and the Bayer Cross that had been lost during World War I. In 2006, Bayer acquired Schering AG for $15.9 billion in a white knight defense against Merck KGaA's hostile bid, adding significant pharmaceutical capabilities including the Mirena contraceptive franchise and oncology assets. The Schering acquisition was the largest in Bayer's history until the Monsanto deal. In 2015, Bayer spun off its materials science division as Covestro through an IPO, focusing the remaining company on life sciences. The transformative—and ultimately disastrous—Monsanto acquisition was announced in May 2016, when Bayer offered $62 billion for the U.S. agricultural biotechnology company. After initial rejection, Monsanto agreed to a $66 billion offer in September 2016. Regulatory approval required divestment of significant agricultural assets to BASF, and the deal closed on June 7, 2018. The Monsanto brand was discontinued, with products rebranded under Bayer. At closing, the acquisition was the largest ever by a German company. Within months of closing, the first Roundup cancer verdict was delivered: a California jury awarded $289 million (later reduced to $78 million) to Dewayne Johnson, a school groundskeeper who claimed glyphosate caused his non-Hodgkin lymphoma. The verdict triggered a cascade of litigation that has now exceeded 165,000 claims and cost Bayer over $17.4 billion in settlements, provisions, and legal fees. By 2023, Bayer's market value had declined by over 60% from its 2016 pre-acquisition peak, leaving the company's overall worth at less than half of what it paid for Monsanto alone.