Natroun over 2400 metres at Longchamp Racecourse on 7 May. Two weeks later he contested the Prix de l'Avre over the same course and distance and won by five lengths from Bilal. Following the race, the colt's owner paid a supplementary entry fee of approximately £15,200 to enter the horse in the Prix du Jockey-Club, reportedly at the urging of Saint-Martin. On 7 June, Natroun contested the 150th running of the Prix du Jockey-Club over 2400 metres at Chantilly Racecourse. In France, horses in the same ownership or stable are coupled for betting purposes. The Vincent O'Brien pair Ancient Times and
Prix Greffulhe the Prix Lupin, the Prix Hocquart and the Prix Noailles. The Prix Greffulhe was restricted to the produce of mares born and bred in France. It was funded by entries submitted before a horse's birth, in the year of conception. The race was abandoned throughout World War I, with no running from 1915 to 1919. It was contested at Le Tremblay over 2,150 metres from 1943 to 1945. The Prix Greffulhe was transferred to Saint-Cloud and shortened to 2,000 metres in 2005. Twenty-three winners of the Prix Greffulhe have achieved victory in the Prix du Jockey Club. The first was