Frederick II

(born Dec. 26, 1194, Jesi, Ancona, Papal States—died Dec. 13, 1250, Castel Fiorentino, Apulia, Kingdom of Sicily) King of Sicily (1197–1250), duke of Swabia (1228–35), German king (1212–50), and Holy Roman Emperor (1220–50). The grandson of Frederick I Barbarossa, he became king of Sicily at age three but did not gain control over the strife-ridden country until 1212. He defeated his rival Otto IV in 1214, and though the planned union of Sicily and Germany alarmed the pope (1220), he negotiated a compromise and was crowned emperor. A delay in departing for the Sixth Crusade brought excommunication (1227), later revoked. By 1229 Frederick was king of Jerusalem. On his return he quelled a rebellion in Germany led by his son Henry, who had allied with the Lombard League. Seeing Frederick as a growing threat to papal authority, Gregory IX excommunicated him again in 1239; the emperor responded by invading the Papal States. He tried and failed (1245) to negotiate peace with Innocent IV, and his struggle with the papacy continued. By the time of his death Frederick had lost much of central Italy, and his support in Germany was uncertain.