She was taken in a slave raid in Ruthenia, in what is now Ukraine, at around 15. Her birth name is gone. The Anastasia and Alexandra that Western books attach to her are inventions of later European folklore, not history. What survives is the name the imperial harem gave her: Hurrem, the joyful one. She arrived in Constantinople at the height of Ottoman power, into an institution that has been badly served by centuries of romanticized Western painting. The harem was closer to a high-security political breeding program, a place where women were educated in language, music, and theology while the only real prize was producing a son and keeping him alive.

The rule that governed everything was one concubine, one son. The moment a boy was born, his mother's relationship with the sultan ended, and when he came of age she left the capital with him ...