Horseracing (as we understand the term today) first took place in Newmarket in 1605. It was banned during the Cromwellian period, but became popular again in the late 17th and early 18th century when Queen Anne played a part in establishing Royal Ascot. The Jockey Club, the sport's regulatory body, was founded in 1750.
Today, there are 60 racecourses in Britain, including those at Bath, Beverley and Brighton, venues which by the 18th century were all associated with horseracing. There may, of course, have been other racecourses beginning with 'B' in operation in the 18th and early 19th century!