This American Grade I stakes race for three-year-old thoroughbreds, is held annually on the third Saturday in May at the Pimlico Race Course in Baltimore.
It is the second leg of the American Triple Crown (Kentucky, Preakness and Belmont). Only 11 horses have ever won the Triple Crown - none since 1978.
The new stakes race was introduced in 1873, two years before the Kentucky Derby was run for the first time.
The Preakness Stakes is known as the "Run for the Black-Eyed Susans", as a horseshoe of Black-Eyed Susans, the state flower of Maryland, is placed around the winner's neck. Amongst the other quaint traditions that surround the race is the practice of painting the racehorse-shaped weathervane on the old clubhouse in the colours of the winning horse and trainer.
In 2013, the Championship will be celebrating its 138th anniversary.