Three-day eventing legend Biko, the 17.3-hand former Olympic mount of U.S. equestrian Karen O’Conner, has been euthanized. He was 30.

The Irish Thoroughbred gelding was an “ambassador for the sport of eventing” and a “stalwart of the U.S. team” in the 1990s, the United States Eventing Association (USEA) said. After earning a silver medal with O’Connor at the 1996 Olympic games in Atlanta, Biko received the USEA’s penultimate “Horse of the Century” award for the 20th century. In 2006 he was inducted into the USEA Hall of Fame.

The Irish-born horse with his famous and flashy white blaze was named for South African anti-apartheid activist Steve Biko, said William Micklem, coach, breeder of elite sport horses, and author of "The Complete Horse Riding Manual." Micklem, of Enniskerry, Ireland, bought and named Biko as a 3-year-old and trained him for two years before selling him to the late Dick and Vita Thompson for O’Connor to ride.

“Biko was a truly magnificent horse because he had such fine qualities all around, which is really unusual,” Micklem told The Horse. “He was beautiful; he had exceptional strides, jump, and gallop, with fantastic technique and scope. He could have been a racehorse, like his brother Jumbeau, or he could have been a show jumper. He turned out to be an impressive eventing horse, which is no surprise. He had no fear of jump heights or water, and he had gallop to spare.”

Biko’s one “weakness,” however, was