Isabella I of Castile (1451–1504), also known as Isabella the Catholic, was Queen of Castile and León from 1474 until her death. Through her marriage to Ferdinand II of Aragon, she also became Queen of Aragon from 1479. Reigning together over a dynastically unified Spain, the pair are known as the Catholic Monarchs. Her reign marked the end of the Reconquista and the start of the Spanish Empire, which made Spain a major force in European politics.