The King and Queen watched on as their horse competed at Doncaster racecourse – but it finished third and missed out on being the first royal winner of the St Leger in more than 45 years.
Charles and Camilla were in position to watch their thoroughbred Desert Hero take on some of the best horses in the country on Saturday.
Bred by the late Queen, the William Haggas-trained colt Desert Hero won two of his three juvenile starts, demonstrating his stamina and talent and fuelling speculation he could end the decades-long wait for the monarchy.
But the royal runner finished third and Continuous gave Aidan O’Brien his seventh win in the Betfred St Leger.
Sent off at 3-1, the son of Heart’s Cry proved two-and-three-quarter lengths too strong for 11-4 favourite Arrest, who was ridden by Frankie Dettori.
The King also had the chance to say farewell to Dettori, with the St Leger being the jockey’s final Classic before retiring.
Dettori won over 50 races for the late Queen during his 35-year career in the saddle.
To mark his retirement, punters, celebrities and stars of racing have been signing a giant card, created by St Leger sponsors Betfred.
Charles and Camilla took on the late Queen’s stable of racehorses after her death last September, and they watched as Desert Hero won the King George V Stakes this summer to give them their first Royal Ascot win.