Marju, runner-up in Generous' Derby in 1991 before winning the St James's Palace Stakes, has died at the age of 28.
The Last Tycoon stallion spent his stallion career at Derrinstown Stud, who have reported his death by natural causes.
A statement posted by Derrinstown read: "A three-parts brother to brilliant filly Salsabil, Marju showed himself to be one of the best milers of his generation when winning the Royal Ascot one-mile championship for three-year-olds after his fine run at Epsom.
"Marju, who was owned by Sheikh Hamdan Al Maktoum and trained by John Dunlop, was retired to Derrinstown in County Kildare at the end of that season (1991).
"He proved an instant success at his new career with winners at the top level, siring the Prix Vermeille and Yorkshire Oaks winner My Emma, and the Prix de Diane winner Sil Sila from his first crop.
"Further Group One successes followed with the likes of Soviet Song, Bethrah, Lightening Pearl and Marbye in Europe, Viva Pataca and Indigenous in Hong Kong, Chinchon in the USA and Marju Snip in Australia.
"In all, he was responsible for 12 individual winners of 21 Group One races during his 19 years at stud.
"Marju's influence as a broodmare sire is still being felt on the racecourses of Europe, epitomised by the recent Prix de l'Abbaye winner, Marsha. Her dam, Marlinka, was by Marju."