High-profile sire Royal Academy has died at Coolmore Australia, ending one of the last links to Nijinsky.

The 25-year-old stallion, who had been retired from stud duties for two years, died on Wednesday as a result of the effects of old age.

“Royal Academy has been a tremendous servant to Coolmore, wherever he’s been based,” Tom Magnier, Coolmore Australia’s racing and new business manager, said.

“He has been wonderfully prolific, siring more than 160 stakeswinners and his progeny earnings are the equivalent of more than $US120,000,000.”

Trained by Vincent O’Brien, Royal Academy’s big-race wins included a July Cup at Newmarket and a Breeders Cup Mile at Belmont Park.

He entered stud in 1991 and produced the likes of Oscar Schindler, Kenwood Melody and 2002 Blue Diamond Stakes winner Bel Esprit, the sire of Black Caviar.