Vincent Motorcycles, "the makers of the world's fastest motorcycles", began with the purchase of HRD Motors Ltd less the factory premises, by Phil Vincent in May, 1928.

HRD was founded by the British Royal Flying Corps (RFC) pilot, Howard Raymond Davies, who was shot down and captured by the Germans in 1917. Legend has it that it was while aprisoner 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 (JA Prestwich Industries) engines.

Unfortunately, although HRD motorcycles won races, the company ran at a loss. 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.

In 1937 Phil Irving went to work for Velocette but returned to Vincent Motorcycles in 1943. Vincent primarily made munitions, but Vincent engines were trialled in boats and portable pumps during the war, and the end of hostilities saw Vincent ready to return to motorcycle production.

Vincent already looked to America for sales, and in 1944 Eugene Aucott opened the first USA dealership in the city of Philadelphia. Others followed.

At a Vincent Owners' Club dinner in the summer of 1955, Phil Vincent announced that the company could no longer continue in the face of heavy losses and that production of motorcycles would cease almost immediately.

In 1955, one week before Christmas, the last Vincent came off the production line and was promptly labeled "The Last."

Source: wikipedia.com