Ferdinand II (Aragonese: Ferrando; Catalan: Ferran; Basque: Errando; Spanish: Fernando; 10 March 1452 – 23 January 1516) was King of Aragon from 1479 to his death, and by his marriage King of Castile from 1474 to 1504 as Ferdinand V. He reigned over a dynastically unified Spain jointly with his wife Isabella I of Castile; together they are known as the Catholic Monarchs. Ferdinand is considered de facto the first king of Spain, being described as such during his own lifetime, although Castile and Aragon remained de jure two different kingdoms until the Nueva Planta decrees of 1707 to 1716. The Crown of Aragon that Ferdinand inherited in 1479 included the kingdoms of Aragon, Valencia, Majorca, Sardinia, and Sicily, as well as the Principality of Catalonia. His marriage to Queen Isabella I of Castile is regarded as the "cornerstone in the foundation of the Spanish monarchy". Ferdinand had a role in the European discovery of the New World, having sponsored the first voyage of Christopher Columbus with Isabella in 1492. That year the couple defeated Granada, the last Muslim state in Western Europe, thus finishing the centuries-long Reconquista. Ferdinand was the king of the Crown of Castile until Isabella's death in 1504. That year, after a war with France, he conquered the Kingdom of Naples. In 1507 he became regent on behalf of their daughter, Queen Joanna of Castile, who was alleged to be mentally unstable. In 1506, as part of a treaty with France, Ferdinand married Germaine of Foix, but there were no surviving children. In 1512 he conquered the Kingdom of Navarre, ruling all the territories comprise modern-day Spain until his death in 1516. He was nominally succeeded by his daughter Joanna but power was soon assumed by her son Charles I.