Frederick II. was nearly twenty-two years old when the death of Innocent III. allowed him to govern as well as to reign. He was of middle height, and well proportioned, though becoming somewhat corpulent as he advanced in age. He had good features and a pleasant appearance. His light hair, like that of his father and grandfather, inclined towards redness, but he ultimately became very bald. Despite his troubled childhood, passed in solitude and gloom at the palace of Palermo, he had been carefully educated. He became familiar with many tongues, and versed in many literatures. The half-Greek, half-Arabic cultivation of Sicily had thoroughly permeated a spirit in which keen rationalism and dreamy mysticism were curiously interwoven. He had a true mediæval love for dialectic. He delighted in geometry and in astronomy. He regulated his public and private life by the predictions of his astrologers, among whom Michael Scot held the first place. He was curious in natural history, collecting a great menagerie of strange animals and studying their habits and structure. The camels and dromedaries, employed in carrying his baggage train, excited the wonder of the Italians, and his elephant, a present from the Sultan of Egypt, was almost as famous as the elephant of Charlemagne. In his concern for his own health he busied himself with surgery and medicine, while his care for his animals turned his interests towards veterinary science. He enjoyed hunting and hawking, not only as a sportsman, but as a naturalist. He wrote a treatise on falconry that attests his zoological and anatomical knowledge. Yet with all his love of fresh air and exercise, he was a valetudinarian who depended upon his physicians almost as much as upon his astrologers, regulating his life and diet very carefully, and indulging so frequently in baths that his enemies reproached him with bathing on Sundays.