How did Philip II become king?

Philip II was born on May 21, 1527, in Valladolid, Spain. Philip was the son of Charles V—the reigning Holy Roman emperor—and Isabella of Portugal. Philip was prepared to succeed Charles almost from birth. As a child, Philip sometimes received secret memoranda from his father reminding him of the responsibility he bore as his father’s successor and warning him to be wary of advisers. Charles gradually increased Philip’s responsibilities as he aged. In 1540 Charles gave the duchy of Milan to Philip. In 1555 Charles resigned the Netherlands to Philip. In 1556 Charles resigned the kingdoms of Spain, the Spanish overseas empire, and the Franche-Comté to Philip. Philip eventually succeeded to all but one of his father’s dominions.