Which horse owned by the Prince of Wales, won the Derby, 2000 Guineas and the St. Ledger in 1900?

Diamond Jubilee (1897 – 10 July 1923) was a British-bred and British-trained Thoroughbred race horse and sire. In a career which lasted from June 1899 until October 1901 he ran sixteen times and won six races.

He showed modest form as a two-year-old in 1899 but improved to be the leading colt of his generation in 1900 when he won the British Triple Crown. The British Triple Crown consists of the Derby, 2000 Guineas and the St. Ledger. His other wins included the Eclipse Stakes, then one of the most valuable horse races in the world. He was retired to stud at the end of the 1901 season and was later exported to Argentina.

Diamond Jubilee was bred by his owner, the Prince of Wales. He was foaled in the year of Queen Victoria's Diamond Jubilee.

Diamond Jubilee's sire, St. Simon was an undefeated racehorse who was considered one of the best British runners of the 19th Century. In an outstanding stud career he won nine sires’ championships, having sired ten Classic winners. Perdita, the dam of Diamond Jubilee was a successful racehorse who was bought by the Prince on the advice of John Porter. As a broodmare she produced, in addition to Diamond Jubilee, the 1897 Derby winner Persimmon and the Jockey Club Cup winner Florizel II. Such was the quality of Diamond Jubilee's pedigree, and the status of his owner, that his birth was noted in the press.