The latest news and top stories on Aidan O’Brien, an Irish horse trainer. He has been the private trainer at Ballydoyle Stables for Coolmore Stud since 1996. He holds records for 10 Epsom Derby victories and 91 Royal Ascot wins. O’Brien achieved a world record 28 Group 1 wins in 2017 and has been Irish Champion Flat trainer since 1999. His expertise lies in developing champion horses, including the notable Delacroix.