Giovio describes him as having been a remarkably sedate and thoughtful boy, so wise beyond his years that his friends feared he would not grow to man's estate.

No pleasures in after-life drew him away from business.

Hunting, hawking, women, had alike no charms for him.

He took moderate exercise for the preservation of his health, read and meditated much, and relaxed himself in conversation with men of letters.

Pure intellect, in fact, had reached to perfect independence in this prince, who was far above the boisterous pleasures and violent activities of the age in which he lived.