On the basis of the livery of the groom in the present picture, the owner of the liver chesnut racehorse is likely to have been Evelyn Pierrepoint, 2nd Duke of Kingston, whose racing colours were crimson and the horse is likely to be Jolly Roger. Jolly Roger, a chesnut gelding, was the only horse that the Duke of Kingston had in training for many years and between 1747 and 1751. He won races at places such as Lincoln, Peterborough, and Grantham, which were in the area of his great Nottinghamshire house Thoresby Park. Having started with Jolly Roger, the Duke of Kingston was to become an important racehorse owner and member of the Jockey Club and many of his horses were painted.
James Seymour was born in London, the son of a banker, goldsmith, and diamond merchant, who supplied plate for racing trophies. Seymour's father was also an amateur artist and a member of the Virtuosi Club of St. Luke, to which the leading sporting artists John Wootton and Peter Tillemans belonged. It is therefore perhaps not suprising that Seymour should have chosen the career of an artist. Although Seymour had no formal training, he began to draw at early age and Vertue mentions that 'from his infancy' he 'had a genius to drawings of Horses'. He also studied pictures and prints in his father's collection and copied old masters. Encouraged by his father, he received an entree into the London art world with introductions to the leading artists of the day. Seymour worked largely at Newmarket and attracted many patrons as well as developing a strong interest of his own in racing and may have owned his own horses.