Ferdinand and Isabella were the Catholic Monarchs of Spain, ruling from 1479 to 1516. They united the kingdoms of Castile and Aragon through their marriage in 1469, which laid the foundation for modern Spain. Their reign is notable for the completion of the Reconquista, the expulsion of Muslims and Jews, and the sponsorship of Christopher Columbus's 1492 voyage, which led to the discovery of the Americas. Their policies strengthened royal authority and centralized power, leading to significant changes in Spanish society. They also established the Spanish Inquisition to maintain Catholic orthodoxy. Ferdinand and Isabella's legacy includes the unification of Spain and the beginning of its global empire.