Frankie Dettori won his first Epsom Derby in 2007 after how many unsuccessful attempts?

Lanfranco "Frankie" Dettori, (born 15 December 1970) is an Italian horse racing jockey in the United Kingdom. Dettori has been Champion Jockey on three occasions and has ridden the winners of more than 500 Group races. His most celebrated achievement was riding all seven winners on British Champions' Day at Ascot in 1996.

The Epsom Derby was the only British Classic Race Dettori had not won in his career, until his fifteenth attempt on 2 June 2007 on the Peter Chapple-Hyam trained Authorized. The following day he won the Prix du Jockey Club on Lawman, notching up a derby double.

Media attention ahead of the 2007 Derby focused on Frankie Dettori who, despite winning all the other British Classics at least twice each, had so far failed to win the Derby in 14 attempts. For the race itself, run at Epsom Downs Racecourse on 2 June 2007, Authorized was a clear favourite at odds of 5 to 4, and justified the odds by winning by five lengths in a fast time. Dropped back in the field early on, he came to join the leaders inside the final two furlongs and won comfortably. His winning margin has not been bettered since Slip Anchor won in 1985 and in a faster time than either Motivator in 2005 or Sir Percy in 2006.