Queen Elizabeth II's staying filly Estimate also will try the 2 1/2-mile marathon that was first run in 1807. The race is carded as the day's third event, with an approximate post time of 10:45 EDT.
A 4-year-old Monsun filly trained by Sir Michael Stoute, Estimate won the 2012 Queen's Vase (Eng-III) going two miles at Royal Ascot. She comes in comes in off a victory May 1 at Ascot in the two-mile Longines Sagaro Stakes (Eng-III) in which she tracked the early leaders, took control over a furlong out, and stayed on strongly to win by 1 3/4 lengths, an indication that she should handle the Gold Cup's extra half-mile.
A former hurdler who won the 2010 Gold Cup, Rite of Passage's career has been compromised by injury and he has made only two subsequent starts in the last three years. After his neck win over Age of Aquarius in the 2010 Gold Cup, the 9-year-old Giant's Causeway gelding got 11 months off, then returned to finish third behind Fame And Glory in the Saval Beg Stakes in May 2011 at Leopardstown. He was off 16 more months, and then won the 2012 QIPCO British Champions Long Distance Cup (Eng-III) by a neck Oct. 20 at Ascot in his comeback and most recent start.
Rite of Passage is trained by Dermot Weld for Dr. Ronan Lambe.
Michael O'Flynn's Saddler's Rock will try to snap winless skein of six races that followed his victory in the 2-mile Artemis Goodwood Cup (Eng-II) last August for trainer John Oxx. That effort by the 5-year-old Sadler's Wells horse followed a third-place finish behind winner Colour Vision last year's Gold Cup.
Godolphin's Colour Vision, a 5-year-old Rainbow Quest gelding trained by Saeed bin Suroor, has not won in five races since capturing the 2012 Gold Cup by a half-length from Opinion Poll, a victory that followed a win over Red Cadeaux in the Sagaro Stakes the previous month.
Trainer John Dunlop will send out Times Up, who closed last season with consecutive wins in the Weatherbys Insurance Lonsdale Cup (Eng-II) in August at York and Doncaster Cup (Eng-II) going 2 1/4 miles in September. He will try to make amends for his sixth-place finish last time out in the Henry II Stakes (Eng-III) May 30 at Sandown.
A raiding party from France includes recent QIPCO Yorkshire Cup (Eng-II) runner-up Top Trip and group winners Vadamar and Last Train. Germany is represented by German and Italian St. Leger winner Altano and German and Italian group I winner Earl of Tinsdal.