Castle Combe, known as the 'friendly circuit' to many, has a long history which has been somewhat blighted by planning and noise wrangles over its lifespan, contributing to keeping the venue as a home for club racing but limiting any higher use.
As with many British courses, it began life as an RAF airfield, built during World War Two as a training ground and home to a fleet of Airspeed Oxfords. It opened in 1941, with its perimeter road (now the race track) being laid around the grass runways in April 1943. The base did not become fully operational until March 1945, two months before VE Day, with the last plane departing in July of that year. Thereafter the site was used as a camp for Polish refugees until 1948, after which it became inactive and was returned to landowners the Gorst family.
One of the landowners, Katherine Gorst, was married to chief designer for Frazer Nash Cars and the engine development man at Bristol Cars, so it was perhaps inevitable that the perimeter road was quickly identified as being suitable for motor racing. The first event, organised by the family and the Bristol Motorcycle and Light Car Club, took place in July 1950, though records do not recall who was the first winner.