Persian King is the second foal of Pretty Please (Dylan Thomas), a half-sister to Planteur (Danehill Dancer), who won the Gr.1 Prix Ganay and was second in the Gr.1 Prix du Jockey Club.

Second dam Plante Rare (Giant's Causeway) is a half-sister to three winners of pattern races, the best of them Policy Maker (Sadler's Wells), who won four Group 2 races and was twice second in the Gr.1 Grand Prix de Saint-Cloud.

Third dam Palmeraie (Lear Fan).

Palmeraie is related to Peinture Bleue (Alydar), winner of the Long Island H., then a Grade 2, in the US and dam of Peintre Celebre (Nureyev). He won the Gr.1 Prix de l'Arc de Triomphe and the Gr.1 Prix du Jockey Club in 1997 and became a leading sire.