CARLOS, DON prince of Asturias, the son of Philip II., king of Spain, by his first wife Maria, daughter of John III. of Portugal, was born at Valladolid on July 8, In 1560 he was recognized as heir to the throne of Castile, and three years later to that of Aragon, but his mental derangement became so acute that in his morbidness he even contemplated the murder of his father. At length, in Jan. 1568, when he had made preparations for flight from Spain, he was placed in confinement by order of Philip, and on July 24 he died. He had not married, though Elizabeth and Margaret, daughters of Henry II. of France, Mary, queen of Scots, and Anne, daughter of the emperor Maxi milian II. had been suggested for him. The marriage of his father and Elizabeth, to whom Carlos had once been betrothed, is be lieved by some writers to have hastened his death. Schiller and Alfieri, J. G. de Campistron in Andronic, and Lord John Russell have made the relations between Don Carlos and his father the subject of dramas; and other dramas based upon the life of Don Carlos have been written by Thomas Otway, M. A. Chenier, J. P. de Montalvan, and D. X. de Enciso.
See L. von Ranke, Zur Geschichte des don Carlos (1829) ; W. H. Prescott, History of the Reign of Philip II., vol. ii. (1855, 1859) L. P. Gachard, Don Carlos et Philippe 11. (5863) ; C. de Moiiy, Don Carlos et Philippe 11. (1863) ; L. A. Warnkonig, Don Carlos, Leben, Verhaftung and Tod (Stuttgart, 1864) ; W. Maurenbrecher, Don Carlos (1876) ; M. Biidinger, Don Carlos, Haft and Tod (1891) ; F. Rachfahl, Don Carlos Kritische Untersuchungen (Freiburg, 1921).