JOANNA (1479-1555), called the Mad (la Loca), queen of Castile and mother of the emperor Charles V., was the second daughter of Ferdinand and Isabella, king and queen of Spain, and was born at Toledo on the 6th of November 1479. Her youngest sister was Catherine of Aragon, the first wife of Henry VIII. In 1496 at Lille she was married to the archduke Philip the Handsome, son of the German King Maximilian I., and at Ghent, in February 1500, she gave birth to the future emperor. The death of her only brother John, of her eldest sister Isabella, queen of Portugal, and then of the latter's infant son Miguel, made Joanna heiress of the Spanish kingdoms, and in 1502 the cortes of Castile and of Aragon recognized her and her husband as their future sovereigns. Soon after this Joanna's reason began to give way. She mourned in an extravagant fashion for her absent husband, whom at length she joined in Flanders; in this country her passionate jealousy, although justified by Philip's conduct, led to deplorable scenes. In November 1504 her mother's death left Joanna queen of Castile, but as she was obviously incapable of ruling, the duties of government were undertaken by her father, and then for a short time by her husband. The queen was with Philip when he was wrecked on the English coast and became the guest of Henry VII. at Windsor; soon after this event, in September 1506, he died and Joanna's mind became completely deranged, it being almost impossible to get her away from the dead body of her husband. The remaining years of her miserable existence were spent at Tordesillas, where she died on the 11th of April 1555. In spite of her afflictions the queen was sought in marriage by Henry VII. just before his death. Nominally Joanna remained queen of Castile until her death, her name being joined with that of Charles in all public documents, but of necessity she took no part in the business of state. In addition to Charles she had a son Ferdinand, afterwards the emperor Ferdinand I., and four daughters, among them being Maria (1505-1558), wife of Louis II., king of Hungary, afterwards governor-general of the Netherlands.
See R. Villa, La Reina doña Juana la Loca (Madrid, 1892); Rösler, Johanna die Wahnsinnige (Vienna, 1890); W. H. Prescott, Hist. of Ferdinand and Isabella (1854); and H. Tighe, A Queen of Unrest (1907).