Thanks to the marriage between Constance, Queen of Sicily, and Henry VI, Holy Roman Emperor, Palermo and the whole Sicily was inherited by their son Frederick II, who became King of Sicily in 1198 and Holy Roman Emperor in 1220. Palermo was the preferred city of the Emperor Frederick II. Muslims of Palermo emigrated or were expelled during Frederick's rule. After an interval of Angevin rule (1266–1282), Sicily came under control of the Aragon and Barcelona dynasties. By 1330, Palermo's population had declined to 51,000.