During part of this period Curzon also served as aide-de-camp to George V. During the First World War, as a keen film maker, he organised the cinematograph service for the Navy.

An associate of the Bentley Boys, he was instrumental in forming the ideas which led Dudley Benjafield to set up the British Racing Drivers' Club in 1928.

He upgraded to an Alfa Romeo 8C for the 1931 24 Hours of Le Mans, and won the race outright driving in partnership with Henry Birkin.

Although patriotic, he was often forced to buy and run cars built outside the UK, as once Bentley had withdrawn from motor sport there were no realistically competitive British-built machines available.

He won the Donington Park Trophy race in 1933, and added to his victory haul with a win in the 1938 Grosvenor Grand Prix, at Cape Town in South Africa.

In addition to these two victories he also took podium finishes in eleven other major races between 1933 and 1939, and became one of only two men to have competed in every running of the RAC Tourist Trophy on the Ards Circuit, the other being Edward Ramsden Hall.

Aside from assuming the presidency of the BRDC, Earl Howe also served as vice-president of the FIA's Commission Sportive Internationale, the governing body of international motorsport at the time.

The start of the Second World War effectively ended Earl Howe's front line driving career, and he returned to the Navy with the rank of commodore.

At the end of the conflict he moved into race organising, although he continued to prepare and enter cars for other drivers, including Tazio Nuvolari.

Under Earl Howe's 35-year stewardship, the BRDC went from private dining club to one of the most successful and high-profile motor sport associations in the world.

In 2017, the Earl Howe Trophy winner was Sam Bird,[4] who won both races at the USA round of the Formula E world championship: the 2017 New York City ePrix.

[6] The inaugural winners under the new criteria were Philip Walker and Gordon Shedden who, together with co-driver Miles Griffiths, won the 2019 Spa Six Hours historic endurance race.

Another daughter (by Sybil Boyter Johnson), Lady Sarah Curzon (born 25 January 1945), married Formula One driver Piers Courage.