Cesario, who won Grade 1 races on two continents and has the distinction of producing three stallion sons at stud in Japan, died at Northern Farm on Saturday aged 19.
Successful in both the Japanese and American Oaks in 2005, the daughter of Special Week was trained by Katsuhiko Sumii, who has in turn received her star progeny and was saddened by the news on the eve of his retirement from the ranks.
From the paddocks Cesario has produced a list headed by Epiphaneia, winner of the Japan Cup and his domestic St Leger who has already sired the Japanese Fillies' Triple Crown heroine Daring Tact.
Her other sons include leading juvenile and Japanese Guineas winner Saturnalia, new to Shadai Stallion Station, and Hanshin Futurity scorer Leontes, whose first crop stars include last weekend's Saudi Derby winner Pink Kamehameha.
Cesario died due to what was described as "the hemorrhagic shock due to ruptured arteries around the uterus".
Northern Farm's Katsumi Yoshida said: "It was suddenly so I was just surprised and felt that my chest tightened. Not only the brilliant race results of winning the Japanese and American Oaks, but also the brilliant broodmare who produced three sires - Epiphaneia who produced the fillies' triple crown winner, Leontes whose son won the Saudi Derby recently, and Saturnalia who entered the stud from this year. I have only words of thanks to her.
