Order Of St George and Stradivarius feature in a nine-strong field for the Gold Cup at Royal Ascot on Thursday.
Order Of St George provided trainer Aidan O’Brien with a record seventh victory in the two-and-half-mile showpiece in 2016 and was beaten a short head by Big Orange when defending his crown 12 months ago.
Just as he did last season, the six-year-old has warmed up for Ascot by running in the Vintage Crop Stakes at Navan and the Saval Beg at Leopardstown and is the narrow favourite for the Gold Cup with some bookmakers.
His main market rival is the John Gosden-trained Stradivarius, who won the Queen’s Vase at last year’s Royal meeting.
The four-year-old was beaten a length into third place by Order Of St George in the Long Distance Cup at Ascot last October, but a winning return in last month’s Yorkshire Cup suggested he could be an improved performer this season.
Jessica Harrington’s Torcedor and the Willie Mullins-trained Max Dynamite join Order Of St George to form a three-pronged Irish challenge, while France’s star stayer Vazirabad is set to make his first appearance in Britain.
Desert Skyline (David Elsworth), Sheikhzayedroad (David Simcock), Scotland (Andrew Balding) and Mount Moriah (Ralph Beckett) complete the line-up.