FREDERICK II. (1194-1250), Roman emperor, king of Sicily and Jerusalem, was the son of the emperor Henry VI. and Constance, daughter of Roger I., king of Sicily, and therefore grandson of the emperor Frederick I. and a member of the Hohenstaufen family. Born at Jesi near Ancona on the 26th of December 1194, he was baptized by the name of Frederick Roger, chosen German king at Frankfort in 1196, and after his father's death crowned king of Sicily at Palermo on the 17th of May 1198. His mother, who assumed the government, died in November 1198, leaving Pope Innocent III. as regent of Sicily and guardian of her son. The young king passed his early years amid the terrible anarchy in his island kingdom, which Innocent was powerless to check; but his education was not neglected, and his character and habits were formed by contact with men of varied nationalities and interests, while the darker traits of his nature were developed in the atmosphere of lawlessness in which he lived. In 1208 he was declared of age, and soon afterwards Innocent arranged a marriage, which was celebrated the following year, between him and Constance, daughter of Alphonso II. king of Aragon, and widow of Emerich or Imre, king of Hungary. The dissatisfaction felt in Germany with the emperor Otto IV. came to a climax in September 1211, when a number of influential princes met at Nuremberg, declared Otto deposed, and invited Frederick to come and occupy the vacant throne. In spite of the reluctance of his wife, and the opposition of the Sicilian nobles, he accepted the invitation; and having recognized the papal supremacy over Sicily, and procured the coronation of his son Henry as its king, reached Germany after an adventurous journey in the autumn of 1212. This step was taken with the approval of the pope, who was anxious to strike a blow at Otto IV.