Vincent Motorcycles was a British manufacturer of motorcycles in the United Kingdom from 1928 to 1955. Their Black Shadow is one of the best known high performance motorcycles of the 1950s. In 1955 the company discontinued motorcycle production due to heavy financial losses. Vincent Motorcycles, "the makers of the world's fastest motorcycles", began with the purchase of HRD Motorcycles, less the factory premises, by Phil Vincent in 1928.
HRD was founded by the British (RFC) pilot, Howard Raymond Davies, who was shot down and captured by the Germans in 1917. Legend has it that it was while a prisoner of war that he conceived the idea of building his own motorcycle, and contemplated how he might achieve that. It was not until 1924 that Davies entered into partnership with E J Massey, trading as HRD Motors. Various models were produced, generally powered by JAP (J A Prestwich) engines.
Unfortunately, even though HRD motorcycles won races the company ran at a loss, and in January 1928 it went into voluntary liquidation. The company was initially bought by Ernest Humphries of OK-Supreme Motors for the factory space, and the HRD name, jigs, tools, patterns, and remaining components were subsequently offered for sale again.