Ruler of the World is a chestnut colt with a narrow white blaze bred in Ireland by Southern Bloodstock, a company associated with the Coolmore Stud.

Ridden by Ryan Moore and racing in padded cheekpieces, he was made the 10/11 favourite against three British-trained opponents in what was described as a "run-of-the-mill" trial.

[5] Ruler of the World overtook the Mark Johnston-trained Mister Impatience a furlong from the finish and drew clear to win by six lengths.

[9] He went clear of the field and was driven out by Moore and won by one and a half lengths from Libertarian, Galileo Rock, and Battle of Marengo.

[10] Ruler of the World was Aidan O'Brien's fourth Derby winner following Galileo, High Chaparral, and Camelot, and gave Moore a second win in the Epsom Classic after his success on Workforce in 2010.

"[13] Following his victory at the 2013 Investec Derby, Ruler of the World was allotted a mark of 120 by the BHA Head of Handicapping, making him the lowest-rated winner of the Epsom Classic this century.

Ridden by Joseph O'Brien, he started the 4/5 favourite in a field which included Libertarian and Galileo Rock, his nearest pursuers at Epsom.

He finished strongly but failed by a short head to catch the Japanese challenger Kizuna, with the favourite, Flintshire, in fourth place.

In his last race of the season, Ruler of the World was dropped back in trip in the 10-furlong Champion Stakes at Ascot on 19 October, two weeks after his run in the Arc.

Under jockey Joseph O'Brien, the colt was well placed behind the leaders early before tiring late on to finish 13th of 16 runners, well behind Godolphin Racing's winner African Story.

Plans to run the colt in the Coronation Cup at Epsom in June were abandoned after he sustained a muscle injury in training.

Ruler of the World led from the start, accelerated clear of his rivals in the straight, and won by one and a half lengths from Flintshire.

On 24 October 2014, it was announced Ruler of the World would be retired to stand at Coolmore stud alongside his father, Galileo, and fellow derby winners Pour Moi, Camelot, and Australia.