 She was from the third crop of foals sired by Harbinger, a British horse who was rated the best racehorse in the world in 2010 when he won the King George VI and Queen Elizabeth Stakes by eleven lengths.Since retiring to stud in Japan his other foals have included Blast Onepiece, Mozu Katchan (Queen Elizabeth II Cup) and Persian Knight (Mile Championship).Deirdre's dam Reizend showed very little racing ability, failing to win in four starts but was a half-sister to the dam of Logi Universe, and a granddaughter of the outstanding racemare Sonic Lady.