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.
With advancing life Frederick’s personal habits grew more and more oriental. He secluded his wives from the public gaze, keeping them under the custody of eunuchs after the Eastern fashion, and maintaining at Lucera a regular harem of concubines, the expenses of which were duly entered in the public accounts of the realm. Though a respectable strategist, Frederick was no warrior, taking small delight in feats of physical skill, and having little of the rough vigour and determination of his chivalrous contemporaries. But he was a subtle and almost a great statesman, who sought to gain his ends by craft, duplicity, and dexterity. Courteous, polished, and seductive in manner, he seemed to belong to a different race from that of his rude Swabian and Norman ancestors. His many-sided character, so full of contradictions, has nothing of the homogeneity and simplicity of the warriors and statesmen of the Middle Ages, but at one time reflects the astute and effeminate oriental, and at another anticipates the accomplished and brilliant despots of the Italian Renascence. His want of sympathy for the ideals of his time comes out strongly in his dealings with the Church. He was believed to have imbibed from his Arab and Jewish masters an utter scepticism as to all religion. Moses, Mohammed, and Christ, he is reported to have said, were three impostors who had deluded the world in turn; and he is also alleged to have maintained that the soul perished with the body. But if Frederick upheld these views before a select circle, he was careful to submit himself to all the obligations of the Church, and to prove his orthodoxy not only by the most formal and positive denials of these charges, but also by a most sanguinary persecution of heresy.