beatty had racehorses trained at beckhampton by fred darling. he purchased the racehorse bois roussel from leon volterra for £8,000, and it went on to win the derby on 1 june 1938. the horse had been listed as having 20 to 1 odds. the win surprised both beatty and many others at the racecourse. king george vi, whose horse, licence, was also entered in the race, invited beatty to the royal box after the win. the derby victory won beatty around $50,000. beatty and prince aly khan were friends and business partners, sharing a love of horses and horse racing. beatty and khan were joint owners of tant mieux, the 1939 winner of the gimcrack stakes.