Prix Jean Prat metres. For a period it was held in April, and it served as a trial for the Prix du Jockey Club. Both Prix Biennal races were renamed the Prix Jean Prat in 1940. This was in memory of Jean Prat (1847–1940), a successful racehorse owner and breeder. The version for three-year-olds was switched to late May or early June in 1961. It was shortened to 1,850 metres in 1962. It was transferred to Chantilly and cut to 1,800 metres in 1967. The present system of race grading was introduced in 1971, and for several years the event held Group 2
Prix du Moulin de Longchamp when the racecourse was built in 1856. The Prix du Moulin de Longchamp was one of two major races introduced to celebrate Longchamp's centenary in 1957. Both initially took place on the first Sunday in October, the same day as the Prix de l'Arc de Triomphe. The other race, the Prix de l'Abbaye de Longchamp, is still held at that meeting. The Prix du Moulin was moved to late September in 1974, and to the first Sunday of that month in 1980. It was formerly contested on Longchamp's middle course (the "moyenne piste"), but was switched to the main course