The Commonwealth Cup is a Group 1 flat race, over 6 furlongs, open to colts and fillies aged three, and was introduced in 2015 as part of a set of changes to the programme of sprint horse races in Europe. The Diamond Jubilee Stakes, run over the same course and distance at the same meeting, was closed to three-year-olds at the same time. The new race was subsequently named the Commonwealth Cup, and the Buckingham Palace Stakes was removed from the Royal Ascot meeting to make room for the new race. The race was initially open to all three year-old-horses, including geldings, to help the race become established. It was the only Group 1 flat race in Great Britain exclusively for three-year-olds that allowed geldings to compete and the first age-restricted Group 1 race which was open to geldings in Europe. Geldings were excluded from the 2020 running.
Early history:- The inaugural running of the Commonwealth Cup took place on Friday 19th June 2015 when won by the Hamdan Al Maktoum owned Muhaarar (10/1) who defeated Limato (9/2), Anthem Alexander (8/1) and 15 others by 3 3/4 lengths and 3/4 length.