Enable, Crystal Ocean and Waldgeist have been jointly named as the top-rated horses in the world for the past year.
Crystal Ocean is to stand at Coolmore's Beeches Stud as a National Hunt stallion.
Crystal Ocean has suffered a career-ending injury during a routine work-out at Newmarket and will be retired to stud.
The Aidan O'Brien-trained Japan has beaten Crystal Ocean in a thrilling finish to the Juddmonte International at York.
Trainer John Gosden has respect for Enable's rivals and is not taking the King George VI And Queen Elizabeth Stakes for granted.
James Doyle will ride Crystal Ocean in the King George VI And Queen Elizabeth Stakes at Ascot with Frankie Dettori to stick with Enable.
Jockey Frankie Dettori has racked up his 62nd Royal Ascot win with a double including Crystal Ocean in the Group One Prince Of Wales's Stakes.
Enable has come through her first race for the season in good order and is primed to defend the Prix de l'Arc de Triomphe.
Prix de l'Arc de Triomphe winner Enable will take on King George runner-up Crystal Ocean when she makes her long-awaited return at Kempton.
William Buick is set to team up with favourite Crystal Ocean in the King George VI And Queen Elizabeth Stakes at Ascot.