Holy Roman Emperor (1519–56) and (as Charles I) King of Spain (1516–56). The son of Philip I (the Handsome) and Joanna of Spain, and grandson of Emperor Maximilian I, Charles came to the throne of Spain in 1516 and united it with that of the empire when he inherited the latter in 1519. Tied down by such wide responsibilities, and hampered by the fact that his authority in his separate territories was established on different bases, Charles was never able to give proper attention to national and international problems. His achievements were none the less considerable. In Spain he survived an early revolt and laid the foundations of the strong government which underpinned Spanish greatness in the century after his death, while in Italy he overcame papal resistance to the establishment of Spanish hegemony. While his long war with Francis I of France was not decisive, it did weaken France to the extent that it was unable to challenge Spain again before the outbreak of the Thirty Years War. He blunted the Ottoman offensive against Christian Europe, and maintained his authority under difficult circumstances in the Netherlands. His greatest failure was in Germany, where he was unable either to check the spread of Protestantism or curb the independence of the local princes. Charles handed Naples (1554), the Netherlands (1555), and Spain (1556) over to his son Philip II, and the imperial crown (1556) to his brother Ferdinand, and retired to a monastery in Spain.