Sir Bevys was a dark brown "almost black" colt standing 15.2 hands high[1] bred at Wytham, Oxfordshire by Lord Norreys.

Sir Bevys was sent into training with Rothschild's private trainer Joseph Hayhoe at the Palace House stable at Newmarket, Suffolk.

[6] Sir Bevys made his 1879 debut on 28 May in the 100th[7] Derby at Epsom, where the large crowd included the Prince and Princess of Wales and other members of the Royal Family.

Ridden by George Fordham, Sir Bevys broke badly and was left many lengths behind the other runners, who were led in the early stages by Protectionaist and Caxtonian.

In the last quarter mile Visconti went to the front and looked the likely winner, but Sir Bevys appeared "from goodness knows where"[1] to take the lead and then hold off the challenge of the 100/1 outsider Palmbearer to win by three-quarters of a length.

The best contemporary explanation offered for the upset, apart from the generally low quality of the race, was that Sir Bevys was the only horse to cope successfully with the very heavy conditions.

Ridden by Tom Cannon, he settled towards the middle of the seventeen horse field but made no progress in the later stages and finished a remote eighth behind Rayon d'Or.