William the Third (horse)

William the Third
William the Third with Morny Cannon up at Ascot Gold Cup
Sire	St Simon
Grandsire	Galopin
Dam	Gravity
Damsire	Wisdom
Sex	Stallion
Foaled	1898
Country	United Kingdom
Colour	Bay
Breeder	William Cavendish-Bentinck, 6th Duke of Portland
Owner	6th Duke of Portland
Trainer	John Porter
Record	14:10-2-0
Major wins
Newmarket Stakes (1901) Ascot Gold Cup (1902) Queen Alexandra Stakes (1902) Doncaster Cup (1902)

William the Third (1898–1917) was a British Thoroughbred racehorse and sire. After finishing unplaced on his only race as a two-year-old in 1900, he won five times in 1901 as well as finishing second in The Derby. He reached his peak as a four-year-old, winning five consecutive races including the Ascot Gold Cup, Queen Alexandra Stakes and Doncaster Cup. His career was ended by injury in early 1903 and he was retired to stud, where he had considerable success as a sire of winners.

William the Third was a bay horse with a narrow white blaze and two white socks bred by his owner William Cavendish-Bentinck, 6th Duke of Portland. Like most of the Duke's horses, he was trained by John Porter at his Kingsclere Stables near Newbury, Berkshire. When fully grown he stood 16 hands high and was described as being of "superb quality" with a "beautiful and intelligent" head.

William the Third was one of the last notable horses sired by St. Simon, 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. His dam, Gravity, was a daughter of the influential broodmare Enigma, the direct female ancestor of many major winners including Reigh Count, Candy Spots and Martial. Gravity herself produced William the Third's full-sister Gravitation, the great-great-granddam of the American Horse of the Year Granville.