Yet splendid as was his career of development in secular affairs, his private life, as well as his public conduct, was stained with flagrant faults, and there was much in his doings that was frowned upon by the pope. New quarrels arose; new wars broke out; the emperor was again excommunicated; the unfortunate closing years of Frederick's career began. Again there were appeals to Christendom; again Frederick's Saracens marched through Italy; such was their success that the pope only escaped by death from falling into the hands of his foe. But with a new pope the old quarrel was resumed, Innocent IV. flying to France to get out of reach of the emperor's hands, and desperately combating him from this haven of refuge.
The incessant conflict at length bowed down the spirit of the emperor, now growing old. His good fortune began to desert him. In 1249 his son Enzio, whom he had made king of Sicily, and who was the most chivalrous and handsome of his children, was taken prisoner by the Bolognese, who refused to accept ransom for him, although his father offered in return for his freedom a silver ring equal in circumference to their city. In the following year his long-tried friend and councillor, Peter de Vincis, who had been the most trusted man in the empire, was accused of having joined the papal party and of attempting to poison the emperor. He offered Frederick a beverage, which he, growing suspicious, did not drink, but had it administered to a criminal, who instantly expired.
Whether Peter was guilty or not, his seeming defection was a sore blow to his imperial patron. "Alas!" moaned Frederick, "I am abandoned by my most faithful friends; Peter, the friend of my heart, on whom I leaned for support, has deserted me and sought my destruction. Whom can I trust? My days are henceforth doomed to pass in sorrow and suspicion."
His days were near their end. Not long after the events narrated, while again in the field at the head of a fresh army of Saracens, he was suddenly seized with a mortal illness at Firenzuola, and died there on the 13th of December, 1250, becoming reconciled with the church on his deathbed. He was buried at Palermo.
Thus died one of the most intellectual, progressive, free-thinking, and pleasure-loving emperors of Germany, after a long reign over a realm in which he seldom appeared, and an almost incessant period of warfare against the head of a church of which he was supposed to be the imperial protector. Seven crowns were his,--those of the kingdom of Germany and of the Roman empire, the iron diadem of Lombardy, and those of Burgundy, Sicily, Sardinia, and Jerusalem. But of all the realms under his rule the smiling lands of Sicily and southern Italy were most to his liking, and the scene of his most constant abode. Charming palaces were built by him at Naples, Palermo, Messina, and several other places, and in these he surrounded himself with the noblest bards and most beautiful women of the empire, and by all that was attractive in the art, science, and poetry of his times. Moorish dancing-girls and the arts and learning of the East abounded in his court. The Sultan Camel presented him with a rare tent, in which, by means of artfully contrived mechanism, the movements of the heavenly bodies were represented. Michael Scott, his astrologer, translated Aristotle's "History of Animals." Frederick studied ornithology, on which he wrote a treatise, and possessed a menagerie of rare animals, including a giraffe, and other strange creatures. The popular dialect of Italy owed much to him, being elevated into a written language by his use of it in his love-sonnets. Of the poems written by himself, his son Enzio, and his friends, several have been preserved, while his chancellor, Peter de Vincis, is said to have originated the sonnet.