Isaac Cullin started his career as a portrait painter, but his interest in horses and artistic skill led him to concentrate on equestrian portraiture.
From 1881 to 1920, Cullin painted racehorses, water-colours of races and numerous other equestrian events. Early examples of his work include Saddling Room, Newmarket and Weighing-In Room, Epsom, which was also produced as an engraving. In 1883 he collaborated with J. A. Wheeler to paint the year's Grand National winner and he later went on to produce sporting illustrations for The Illustrated London News.
As can be seen from another of his works, Tattersall's, Cullin's talent lies in the splendid portrayal of both people and horses in action. His horses are painted strongly, accurately and, many have said, almost photographically, such is the attention paid to detail in every movement.