Joanna I (6 November 1479 – 12 April 1555), known historically as Joanna the Mad (Spanish: Juana la Loca), was Queen of Castile from 1504 and Queen of Aragon from 1516 to 1555. Modern Spain evolved from the union of these two kingdoms. She was married by arrangement to Philip the Handsome, Archduke of Austria of the House of Habsburg, on 20 October 1496. Following the deaths of her brother, John, Prince of Asturias, in 1497, her elder sister Isabella in 1498, and her nephew Miguel in 1500, Joanna became the heir presumptive to the crowns of Castile and Aragon. When her mother, Queen Isabella I of Castile, died in 1504, Joanna became Queen of Castile. Her father, King Ferdinand II of Aragon, proclaimed himself Governor and Administrator of Castile. In 1506 Archduke Philip became King of Cas