Gilles de Retz (horse)

Gilles de Retz (1953–1969) was a British Thoroughbred racehorse and sire best known for winning the classic 2000 Guineas in 1956. After winning twice from five starts as a two-year-old, the colt disappointed on his three-year-old debut before recording a 50/1 upset victory in the Guineas. Although the feat was not officially recognised at the time, Gilles de Retz's success made Helen Johnson Houghton the first woman to train the winner of a British classic. The colt failed to reproduce his best form in three subsequent efforts in 1956 and won once from four attempts as a four-year-old. He was retired to stud where he had little success as a sire of winners.