Affirmed has been waiting for a successor since 1978. Ridden by Steve Cauthen and trained by Lazaro Barrera, the three-year-old was the last horse to win the Triple Crown, following up victories in the Preakness Stakes and Kentucky Derby with success in the Belmont Stakes.
Two horses have come close since then: War Emblem, who was unexpectedly beaten in the final leg by Sarava in 2002; and Smarty Jones, who finished last behind Birdstone in front of an expectant 120,000 crowd two years later.
The last horse to pull off the treble before Affirmed was Seattle Slew just a year earlier, ridden by the Agen-born jockey Jean Cruguet.
In 1973 Secretariat won all three races, the first horse to do so since the 1940s, when Eddie Arcaro became the only jockey to achieve the feat twice, first with Whirlaway in 1941 and then with Citation seven years on.
In the previous decade Jim Fitzsimmons achieved history by saddling up two Triple Crown winners in Gallant Fox in 1930 and Omaha five years later, an achievement no other trainer has yet matched.
The four other horses to have pulled off this most special of hat-tricks are Assault (1946), Count Fleet (1943), Sir Barton (1919), and last but most certainly not least, the legendary War Admiral, who won the Triple Crown in 1937 and became the arch-rival of the much-loved Seabiscuit, their compelling duel being immortalised in a recent film.