William Rootes, 1st Baron Rootes

William (Billy) Rootes was born in Goudhurst, Kent. His father, also William, owned a general engineering business in Goudhurst, which included bicycle production. William (Snr) attended a motor show organised by Sir David Salomons in Tunbridge Wells in 1895. Billy and his brother Reginald (Reggie) shared their father's interest in things mechanical.

Billy attended Cranbrook School, and on leaving school in 1909 was apprenticed to the Singer car company. His father had moved the family business to Hawkhurst by this time, and expanded into the motor trade.

Billy left Singer in 1913 to start his own car agency, independent of his father's business. He sold all of his first batch of cars within a few months of leaving Singer. The business was moved to Maidstone before the First World War, and the firm worked on the maintenance and repair of aero engines during the war.

By 1924, the Rootes company had become the largest truck and car distributor in the United Kingdom. From 1929 it expanded into manufacturing by buying established companies, beginning with Hillman, Humber and Commer. Rootes Group became a major vehicle manufacturer, with overseas distribution and vehicle assembly arms.

During the Second World War, Billy supervised the volume manufacture of aircraft and engines, as well as the supply of military motor vehicles and armoured fighting vehicles.

In the 1950s, he became a leader of Britain's export drive, and chaired a committee to found the University of Warwick with a vision of academic links with industry.

Rootes married his first wife, Nora Press, in 1916. The marriage produced two sons, William Geoffrey Rootes (1917–1992) who between 1967 and 1973 served as chairman of the family business (at that time a subsidiary of Chrysler Corporation and renamed as Chrysler United Kingdom) and Brian Gordon Rootes (1919–1971) who held a succession of senior positions within the company between 1937 and 1967, interrupted by a period of military service during the Second World War.

In 1958, Rootes bought Ramsbury Manor, a country house in Wiltshire.