Mastery is a bay horse sired by Sulamani the winner of several major races including the Prix du Jockey Club and the International Stakes.

His dam Moyesii won only one minor race but was a daughter of the Haydock Sprint Cup and Prix Maurice de Gheest winner Cherokee Rose.

Ridden for the first time by Frankie Dettori he raced just behind the leaders before taking the lead 100m from the finish and winning by one and a half lengths from Turati and Jakkalberry.

He finished third to Holberg in the Queen's Vase at Royal Ascot, third to Cavalryman in the Grand Prix de Paris and second to the Irish-trained Monitor Closely in the Great Voltigeur Stakes.

In September, Mastery was sent to Doncaster for the St Leger in which he was ridden by Ted Durcan, Dettori having chosen to ride the favourite Kite Wood.