High Quality Content by WIKIPEDIA articles! Shergar (1978 - unknown) was an acclaimed Irish racehorse, and winner of the 1981 Epsom Derby by a record 10 lengths, the longest winning margin in the race`s 226-year history. This victory earned him a spot in The Observer newspaper`s 100 Most Memorable Sporting Moments of the Twentieth Century. A bay colt with a distinctive white blaze, Shergar was named European Horse of the Year in 1981 and was retired from racing that September.