War Cloud (1915-1923) was an British-bred Thoroughbred racehorse who was the first horse to compete in all three U.S.Triple Crown races.

Bred by Jack B. Joel, one of Britain's most prominent Thoroughbred owner/breeders, War Cloud was sold as a yearling and brought to race in the United States. Successful racing at age two, War Cloud was the heavy favorite going into the 1918 Kentucky Derby after the U.S. Two-yr-Old Champion Colt Sun Briar was sidelined with ringbone disease. Ridden by Johnny Loftus, War Cloud however finished a disappointing fourth to longshot Exterminator. The Preakness Stakes attracted a very large field and as such had to be run in two divisions. War Cloud won one while Jack Hare Jr. won the other. In the final leg of the Triple Crown races, the Belmont Stakes, War Cloud finished second to Harry Payne Whitney's colt, Johren.

After racing successfully at age four, War Cloud was shipped to France to race in his five-year-old season but did not perform well. He was brought back to stand at stud at Claiborne Farm in Paris, Kentucky but broke a leg in 1923 and had to be euthanized. He is buried in Claiborne's equine cemetery.

source: http://en.wikipedia.org