Blacklock, a bay colt, was foaled in 1814 by Whitelock, out of a mare by Coriander. He was bred by Mr. Kirby and sold to Mr. Watt after his first race, remaining unbeaten prior to the 1817 St. Leger. In this race he started odds on in a field of eighteen but was beaten by a head by Ebor, in sensational circumstances, when his jockey eased him too soon, thinking he had won. He eventually won sixteen of his twenty-two races before breaking down at York in 1819.

Retired to Bishop Burton, near Beverley, he was equally successful as a stallion and was champion in 1829. His best sons were Voltaire and Velocipede whilst his direct descendants include such great horses as Voltigeur, Galopin and St. Simon.