Johnny Murtagh, one of the world's top jockeys, is hanging up his tack to concentrate on training from his base in County Kildare, Ireland.
Murtagh was granted his trainer's license in May 2013 and took over from Tommy Carmody at Fox Covert Stables.
During a 26-year career in the saddle he rode more than 100 top-level winners at in Europe and abroad.
Murtagh captured in each of the five Irish classics at least once, riding four Irish Derby (Ire-I) winners and six Irish Oaks (Ire-I) winners, including last year's French-trained Oaks winner Chicquita.
He also rode three winners of the Epsom Derby (Eng-I) in Sinndar (2000), High Chaparral (2002) and Motivator (2005) and was successful in the Two Thousand Guineas (Eng-I) twice, aboard the brilliant Rock of Gibraltar (2002) and Henrythenavigator (2008).
He also rode Dancing Rain to a front-running victory in the 2011 Epsom Oaks (Eng-I).
Last year, Murtagh enjoyed wins aboard Novellist in the King George VI and Queen Elizabeth Stakes (Eng-I) and with Sole Power in the King's Stand Stakes (Eng-I) at Royal Ascot en route to being the meet's leading rider for the fifth time.
"I went for a run the other day and during it I started to think about the amount of effort that I have to put in this season and I just don't think I have the time to give to being a jockey any more," Murtagh told Racing Post.
"I didn't want to give riding 30% and training 70%. All my life it has been 100% or nothing."
Murtagh spent three seasons as stable jockey to Aidan O'Brien's Ballydoyle operation between 2008 and 2010 and then rode for the Aga Khan until August 2012.