Charles V., (I. of Spain), emperor of Germany, son of Philip, Archduke of Austria, born at Ghent; became king of Spain in 1516, on the death of his maternal grandfather Ferdinand, and emperor of Germany in 1519 on the death of his paternal grandfather Maximilian I., being crowned at Aix-la-Chapelle in 1520; reigned during one of the most important periods in the history of Europe; the events of the reign are too numerous to detail; enough to mention his rivalry with Francis I. of France, his contention as a Catholic with the Protestants of Germany, the inroads of the Turks, revolts in Spain, and expeditions against the pirates of the Mediterranean; the ambition of his life was the suppression of the Protestant Reformation and the succession of his son Philip to the Imperial crown; he failed in both; resigned in favour of his son, and retired into the monastery of St. Yuste, in Estremadura, near which he built a magnificent retreat, where, it is understood, notwithstanding his apparent retirement, he continued to take interest in political affairs, and to advise in the management of them (1500‒1558).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Charles X. * Charles VI.