Johnny was bred in Yorkshire by William Cornforth and bought by Lord Clemont as a colt. By Matchem out of a Babraham mare, he raced at Newmarket with considerable success between 1773 and 1776, and this picture was probably commissioned in circa 1775.
Lord Clermont was M.P. for Co. Louth 1745-61, and later for Monaghan and Dundalk. His maternal uncle James, Earl of Clanbrassil, patronised Stubbs, and Lord Clemont himself probably commissioned another work from the artist: a pointer called Phillis, dated 1772.
Lord Clemont was a keen sportsman and racing enthusiast (he won the Derby with Aimwell in 1785) and was said to have been on intimate terms with the Prince of Wales and Charles James Fox.