Alex Greaves, the winningest female jockey in British racing history, has announced her surprise retirement from the saddle at the age of 36. The first woman to ride a Group 1 winner in England when she partnered Ya Malak to a dead-heat victory with Coastal Bluff in the 1997 Nunthorpe Stakes at York, Greaves was also the first woman to ride in the Epsom Derby and the 1000 Guineas.