Keysoe (horse)

Keysoe (1916–1929) was a British Thoroughbred racehorse and broodmare. Bred and owned by the 17th Earl of Derby she was the product of a mating between two St Leger winners and won the race herself in 1919. She was unraced as a juvenile but developed into a top-class stayer at three, winning the Gratwicke Stakes and the Nassau Stakes at Goodwood Racecourse before taking the St Leger and later winning the Newmarket Oaks. She failed to win as a four-year-old in 1920 although she was placed in all of her races. After her retirement from racing, she had considerable success as a broodmare despite producing very few foals.