The Aga Khan IV, the wealthy leader of the world’s Ismaili Muslims who died on Tuesday at 88, led an eventful life that included resort development, charitable initiatives, a Harvard education and a trip to the Winter Olympics as a skier.

But one of his darkest days was the kidnapping and death of his prized horse, Shergar.

Shergar wasn’t just a winner of the Epsom Derby, Britain’s most prestigious race. He was one of the greatest horses ever to run in the Derby, winning in 1981 as the favorite by 10 lengths, a record that still stands.

As Shergar pulled away for his big Derby win, the radio commentator Peter Bromley said, “There’s only one horse in it; you’d need a telescope to see the rest!”

Shergar won other big races that year, including the Irish Derby, and then was retired at the end of 1981. He was set for a life as a stud horse, with every expectation that he would sire a generation of impressive racehorses. The fee for a mare to mate with him was $100,000.

But in February 1983, armed men forced a groom who cared for Shergar to lead them to the horse’s stable in Newbridge, Ireland. They loaded the horse into a trailer they had brought and drove off. Shergar was never seen again.