He was one of the best horses sired by Brigadier Gerard who won seventeen of his eighteen races between 1970 and 1972 and is rated the second-best British-trained racehorse since 1947 (after Frankel) by the independent Timeform organisation.
Vayrann's dam Val Divine (bred by François Dupré) was a moderate racehorse but a very good broodmare who produced the Queen Anne Stakes winner Valiyar and the Oak Tree Invitational Stakes winner Yashgan as well as the dams of Natroun (Prix du Jockey Club) and Vereva (Prix de Diane).
[3] The Aga Khan bought Val Divine at the dispersal of Dupre's bloodstock: at the time she was carrying the unborn foal who would later be named Vayrann.
Vayrann produced a strong finish to overtake Bikala inside the final furlong and won by half a length, with Storm Bird unplaced.
Ridden by Yves Saint-Martin he started the 15/2 second favourite behind the 2000 Guineas winner To-Agori-Mou in a field which also included the Irish filly Cairn Rouge who had won the race in 1981 as well as Master Willie, Madam Gay and The Wonder.
He looked less than fully fit and ran well to finish fourth behind Bikala, Lancastrian and Al Nasr with Kalaglow and April Run unplaced.
The Aga Khan's team of experts argued that it was possible for a male horse to produce Estrane naturally as a breakdown product from testosterone, and that the Jockey Club's list of prohibited substances only covered those which were administered externally.
[9] He also sired Vayrua, who finished third in Chester Vase before becoming a top-class National Hunt horse, whose wins included the Anniversary Hurdle at Aintree Racecourse in 1989.