Frederick II, Holy Roman Emperor

Frederick II (1194–1250), called Stupor Mundi (Wonder of the World), was King of Sicily, King of the Germans and Holy Roman Emperor. The son of Emperor Henry VI and Constance of Sicily, he was crowned King of Sicily in 1198, went north as King of the Germans in 1212 and was crowned emperor in 1220.

He was excommunicated four times, yet his Sixth Crusade of 1228 recovered Jerusalem by treaty with Egypt. In Sicily he built an absolutist state: he founded the University of Naples in 1224 and issued the Constitutions of Melfi in 1231.

In Italy he fought the Lombard League, defeating it at Cortenuova in 1237, and Pope Innocent IV, who called him the forerunner of the Antichrist. He died of dysentery at Castel Fiorentino on 13 December 1250. His son Conrad IV died in 1254, the Hohenstaufen fell, and the Empire entered the Great Interregnum.