Frederick I, Barbarossa, Holy Roman Emp.
Frederick I, Friedrich Barbarossa (Italian: Redbeard), Duke of Swabia (as Friedrich III, 1147–90) and German king and Holy Roman emperor (1152–90), who challenged papal a...
Frederick II, King of Sicily
Frederick II of the Hohenstaufen dynasty, was a pretender to the title of King of the Romans from 1212 and unopposed holder of that monarchy from 1215. As such, he was Ki...