MEDICIS, Cosmo de, grand duke of Tuscany, joined Charles V. against the French, after trying in vain to continue neutral. As a reward for his services, the emperor added to the duchy of Tuscany Piombino, the isle of Elba, and other states. Cosmo soon after received from Pope Pius IV. the title of grand duke, and had it not been opposed by all the princes of Italy, this pontiff, who was entirely devoted to Cosmo, because he had thought proper to acknowledge him to be of his house, would have conferred on him the title of king. There never was a more zealous patron of learning. Ambitious of imitating the second Cæsar, he like him, was fond of learned men, kept them near his person, and founded for them the university of Pisa. He died in 1574, at the age of 55, after governing with equal wisdom and glory. In 1562 he instituted the military order of St. Stephen. His son, Francis Mary who died in 1587, was the father of Mary of Medici, the wife of Henry the Great and of Ferdinand I. who died in 1608.