Direct contemporaries, born within a month of each other at the turn of the twenty-first century, albeit in France and Ireland, respectively, Kauto Star and Denman became stable companions at Paul Nicholls' Manor Farm Stables in Ditcheat, Somerset. Collectively, they ran in the Cheltenham Gold Cup times and against each other on four occasions, in 2008, 2009, 2010 and 2011.
In the absence of Denman, who had stormed home to a 10-length victory in the Royal & Sun Alliance Chase 48 hours earlier, Kauto Star ran in, and won, the Cheltenham Gold Cup for the first time in 2007. Sent off favourite, at 5/4, Kauto Star quickened to lead at the second-last fence and stayed on strongly in the closing stages to beat Exotic Dancer by 2½ lengths.
The following year, 2008, both horses arrived at the Cheltenham Festival in peak form. Defending champion Kauto Star was once again sent off favourite, but had no answer to Denman, who went clear approaching the third-last fence and was driven out to win by 7 lengths. Denman subsequently received treatment for an irregular heartbeat, which delayed his return to action until February, 2009, and it would be fair to say that he was never quite the same horse again.
Nevertheless, Kauto Star and Denman reopposed in the 2009 Cheltenham Gold Cup, with Kauto Star running out an impressive 13-length winner and, in so doing, becoming the first horse in history to regain his title. They did so again in 2010, with Kauto Star falling at the fourth-last and Denman finishing a tired, 7-length second to Imperial Commander, and again, as 11-year-olds, in 2011. On the latter occasion, Denman once again fared the better of the pair, but proved no match for the 6-year-old Long Run, who stayed on strongly to win by 7 lengths.