Grimalkin was a brown colt foaled in 1808 by Chance out of Jemima by Phenomenon, bred by Mr. T. Duncombe, stud manager to the Prince of Wales. He came to prominence in 1811 when he caused a major upset by winning the Doncaster Cup at what were officially returned as being 'very high odds'. Sold to John, 5th Duke of Rutland the same year, he went on to win seven races at Newmarket in 1812. The year this picture was painted he was sold to the Emperor of Austria as a stallion for 1,700 guineas, and in turn became the property of Ferdinand Graf Trauttmansdorff, who was uncle to the Austrian Ambassador to England. The entry in the 1929 Christie's sale catalogue was preceded by the property title 'The following has recently been purchased by the present owners from the Executors of Furst Trauttmansdorff'.
The group is shown at the finish of the Beacon Course from in front of the King's Stand, with the King's Stables (or Rubbing House) to the right, and the edge of the Duke of Portland's Stand on the left. The figure in the judge's box is John Hilton who was painted several times by Marshall, and the jockey is wearing the Duke of Rutland's colours. The figure on horseback on the left is presumably the trainer, and may have been called Mr Douglas.
A version by Marshall, of the same size but showing an additional grey racehorse and two young grooms on the left hand side of the picture, is in a private collection.