What is "ribero"

Ribero (foaled 1965 in Kentucky) was an American-bred British-trained Thoroughbred racehorse and sire. In a career which lasted from September 1967 until May 1969 he ran twelve times and won three races. He is best known for his performances in 1968 when he won two of the most important European races for three-year-olds; the Irish Derby (in which he defeated Sir Ivor), and the St Leger.