Philip II the Hapsburg was King of Spain from 1556 - 1598. However his father, Charles V, was King during the period of Hurtado de Mendoza's ambassadorship to Rome...
He was the only legitimate son of the Holy Roman Emperor Charles V. His reign marked the apogee of Spanish and Hapsburg power. Flush with wealth from America, Philip ruled an empire stretching around the world. During his reign he faced revolt in the Netherlands; became King of Portugal; fought wars with England and France. As a consequence of these tumultuous events he was also King of Naples and Sicily 1554 - 1558, King of England (co-regent with Mary I) 1554 - 1558, and King of Portugal 1580 - 1598.
By reason of this great devotion, and the great virtues of my Cid, and the miracles which were wrought by him, King Philip the Second gave order to his ambassador Don Diego Hurtado de Mendoza, to deal with the Court of Rome concerning the canonization of this venerable knight Rodrigo Diaz.