Frederick II (German: Friedrich; Italian: Federico; 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.
Frederick II, king of Sicily (1197–1250), duke of Swabia (as Frederick VI, 1228–35), German king (1212–50), and Holy Roman emperor (1220–50). A Hohenstaufen, he pursued his dynasty’s imperial policies against the papacy and the Italian city-states. He also joined in the Sixth Crusade (1228–29).
Frederick II, German Friedrich , (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).
Under the pretext that the emperor intended to drive him from Rome, Gregory excommunicated Frederick for the second time on Palm Sunday, March 20, 1239. This was the beginning of the last phase of the gigantic struggle between the papacy and the empire; it ended with the death of the emperor and the downfall of his house.
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.
Frederick the Second is a biography of Frederick II, Holy Roman Emperor, by the German-Jewish historian Ernst Kantorowicz. Originally published in German as Kaiser Friedrich der Zweite in 1927, it was "one of the most discussed history books in Weimar Germany ",  and has remained highly influential in the reception of Frederick II. 
He arrived in Cyprus on July 21. In Cyprus, John of Ibelin, the leading member of the influential Ibelin family, had been named regent for the young Henry I. Along with most of the barons, he was willing to recognize the emperor’s rights as suzerain in Cyprus.
Frederick II ( German: Friedrich; Italian: Federico; 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 and Queen Constance of Sicily of ...
FREDERICK II, ROMAN EMPEROR. Reigned Nov. 22, 1220 to Dec. 13, 1250. Frederick was born in Jesi, a small city on the eastern side of the Italian peninsula on Dec. 26, 1194. His father was the Emperor Henry VI of the Hohenstaufen family (d. 1197) and his mother was Constance, daughter of Norman King Roger II of Sicily.
Frederick married at age 15, and in March 1212 he had his one-year-old son crowned king of Sicily. In April 1220 the same child was elected king of Germany as Henry VII. After defeating a rival emperor, Frederick was himself crowned Holy Roman emperor on Nov. 22, 1220. Frederick was an intelligent and capable ruler.