Rock Of Gibraltar, the first horse ever to win seven consecutive Group Ones in the northern hemisphere, has died of heart failure at the age of 23.

Winner of the Grand Criterium and the Dewhurst Stakes in the autumn of his juvenile campaign, the Aidan O'Brien-trained son of Danehill went on to enjoy an exceptional three-year-old season 20 years ago.

After beating stablemate Hawk Wing in the 2000 Guineas, Rock Of Gibraltar went on to carry the colours of part-owner Sir Alex Ferguson to further top-level victories in the Irish 2,000 Guineas, the St James's Palace Stakes at Royal Ascot, the Sussex Stakes at Goodwood and the Prix du Moulin in France.

He rounded off his racing career by finishing a close second to Domedriver in that year's Breeders' Cup Mile at Arlington Park.

At stud he sired a total of 16 Group or Grade One winners including Coral-Eclipse victor Mount Nelson and Golden Jubilee and Haydock Sprint Cup hero Society Rock.

Rock Of Gibraltar was also a notable broodmare sire, with two of his daughters producing two recent 2000 Guineas winner in Kameko and Poetic Flare.

Paddy Fleming, manager at Coolmore's Castlehyde Stud, said: "He was healthy and looking great right up to the end.

"He was a fantastic racehorse and a very good sire who will be missed by all the staff here."