The story begins with A. Darracq et Cie, a French car manufacturer founded in 1896 by Alexandre Darracq in Suresnes, near Paris, following the sale of his Gladiator bicycle business. In 1902, Darracq sold the French company to a newly created English firm, A Darracq and Company Limited, incorporated in Britain because French law made the necessary share flotation processes more difficult. The British group was headed by William Beilby Avery and included a London lawyer and a retired army officer; Darracq himself retained just under 50 percent of shares in the new venture.
The company prospered. By 1903 four models were offered, and by 1904 the Darracq Flying Fifteen — a 3-litre four powered by a chassis made from a single sheet of pressed steel — had captured ten percent of the French automobile market. Six world speed records were held simultaneously by Darracq cars by 1905. Almost 75 percent of 1904 output was exported.
Problems emerged when Alexandre Darracq, against sound engineering advice, insisted on equipping a new model with the unproven Henriod rotary valve engine. The engine proved underpowered and prone to seizing, damaging the marque's reputation. Darracq resigned in 1911 and sold his shares. Under new managing director Paul Ribeyrolles and works manager Owen Clegg — who sensibly replicated a proven Rover design for the new Darracq model — the Suresnes factory was retooled for semi-mass production, and by 1914 some 1,200 workers were producing 14 cars per day.
After the First World War, A Darracq and Company went on an acquisition spree. In late 1919 it bought Clément-Talbot, the Kensington-based British car manufacturer. In June 1920 it acquired control of the Sunbeam Motor Car Company of Wolverhampton. In August 1920 the parent company was renamed S.T.D. Motors Limited to reflect the gathering of Sunbeam, Talbot, and Darracq under one roof, with each marque retaining its separate identity and manufacturing site.
The three brands served distinct markets and geographies: Sunbeam cars were built at Moorfield Works, Wolverhampton; Talbot at Clément-Talbot in North Kensington, London; and the French operation continued at Suresnes, initially badged Talbot-Darracq before the Darracq name was dropped from the French products in 1922 and the Suresnes business was renamed Automobiles Talbot.
S.T.D.'s chief engineer Louis Coatalen used the group's racing activities to drive technical development and public profile, primarily under the Sunbeam name. Sunbeam won the French Grand Prix in 1923 and was competitive throughout the mid-1920s on the European Grand Prix circuit. Henry Segrave's 1923 French GP win at Tours in a Sunbeam was Britain's first Grand Prix victory. The Suresnes-based Talbot-Darracq operation also produced competitive voiturette and Grand Prix machinery.
In 1924, S.T.D. Motors borrowed from the public, funds that were widely believed to support Coatalen's racing ambitions. The racing programme delivered prestige results but at considerable cost that the group's finances struggled to absorb.
Increased profits never materialised to match the group's spending. By the late 1920s, financial reserves were exhausted and the product range was becoming obsolete. A court-sanctioned financial reconstruction in June 1930 recognised substantial accumulated losses and reduced ordinary capital to one-third of its value.
In late 1931, the entire STD Motors board resigned under shareholder pressure and a new board under General Sir Travers Clarke was installed. The company's 1924 borrowings fell due in early 1934 and could neither be repaid nor refinanced. In mid-October 1934, lenders applied to the High Court for the appointment of receivers to Sunbeam and Clément-Talbot.
The disintegration followed quickly. The Rootes Group acquired Clément-Talbot and the Darracq Motor Engineering Company, and subsequently purchased Sunbeam and its commercial vehicle subsidiary from the receiver in the summer of 1935. The former Talbot business in France was acquired by Antonio Lago, the Suresnes plant's managing director, who created Talbot-Lago. STD Motors thus ceased to exist, its constituent parts absorbed into other enterprises.