Frederick II (Italian: Federico, Sicilian: Fidiricu, German: Friedrich, Latin: Fridericus; 26 December 1194 – 13 December 1250) was King of Sicily from 1198, King of Germany from 1212, King of Italy and Holy Roman Emperor from 1220 and King of Jerusalem from 1225. He was the son of Emperor Henry VI of the Hohenstaufen dynasty (the second son of Emperor Frederick Barbarossa) and Queen Constance I of Sicily of the Hauteville dynasty.
Frederick was one of the most brilliant and powerful figures of the Middle Ages and ruled a vast area, beginning with Sicily and stretching through Italy all the way north to Germany. 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 co-ruler with his mother, Constance, Queen of Sicily, 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. Frequently at war with the papacy, which was hemmed in between Frederick's lands in northern Italy and his Kingdom of Sicily (the Regno) to the south, he was "excommunicated four times between 1227 and his own death in 1250", and was often vilified in pro-papal chronicles of the time and after. Pope Innocent IV went so far as to declare him preambulus Antichristi (forerunner of the Antichrist).