Sinndar, the winner of two Derbys and the Prix de l’Arc de Triomphe at three, has died aged 21.
He won seven of his eight starts including the Irish and Epsom Derbys in 2000 and capped his career with victory in the Arc for trainer John Oxx and his owner/breeder, the Aga Khan.
Sinndar was retired from stud duties at Haras d’Ouilly at the end of the 2017 breeding season.
“It is with great sadness that the Aga Khan Studs announce the passing of Sinndar at the age of 21,” a statement on agakhanstuds.com said.
“A Group One winner at two and crowned European Champion Three-Year-Old in 2000, Sinndar remains the only horse to have won the Derby, the Irish Derby and the Prix de l’Arc de Triomphe at the age of three.”
During his career at stud, Sinndar sired Group One winners Rosanara, Shareta, Shawanda and Youmzain, who was runner-up in the Prix de l’Arc de Triomphe for three consecutive years.
Sinndar’s last crop of foals were born this year.