Frederick II (26 December 1194 – 13 December 1250) was one of the most powerful Holy Roman Emperors of the Middle Ages and head of the House of Hohenstaufen. His political and cultural ambitions, based in Sicily and stretching through Italy to Germany, and even to Jerusalem, were enormous. However, his enemies, especially the popes, prevailed, and his dynasty collapsed soon after his death. Historians have searched for superlatives to describe him, as in the case of Professor Donald Detwiler, who wrote:
Viewing himself as a direct successor to the Roman Emperors of Antiquity, he was Emperor of the Romans from his papal coronation in 1220 until his death; he was also a claimant to the title of King of the Romans from 1212 and unopposed holder of that monarchy from 1215. As such, he was King of Germany, of Italy, and of Burgundy. At the age of three, he was crowned King of Sicily as a co-ruler with his mother, Constance of Hauteville, the daughter of Roger II of Sicily. His other royal title was King of Jerusalem by virtue of marriage and his connection with the Sixth Crusade.