Aidan O'Brien is Flat racing's towering force - but will his jumping counterpart upset the Gold Cup script?

Aidan O'Brien has achieved almost everything there is to achieve, particularly on the starriest stage of Royal Ascot, yet Flat racing's pre-eminent force will have done something even he has never done before if Kyprios justifies favouritism in the meeting's signature prize.

O'Brien is the most successful trainer in the history of Royal Ascot and has lifted the Gold Cup on eight occasions, more than anyone in the race's 217-year history. The master of Ballydoyle was also the genius behind Yeats, the great marathon's one and only quadruple winner. What O'Brien has yet to do is produce a horse to regain the Gold Cup, a feat achieved only by Anticipation in 1816 and 1819 and, more recently, by Kayf Tara in 1998 and 2000. What they did then, Kyprios attempts to do now.

It was two years ago that Kyprios placed his name on the Gold Cup's honour roll, defeating Mojo Star and Stradivarius in a pulsating finish. Victory at Ascot was followed by wins in the Goodwood Cup and Irish St Leger before the son of Galileo did something extraordinary in Paris, claiming France's Gold Cup, the Prix du Cadran, by 20 lengths.