The "Queen of Aragon" typically refers to Isabella I of Castile, who, along with her husband Ferdinand II of Aragon, unified Spain in the late 15th century. They are known for completing the Reconquista, which ended Muslim rule in the Iberian Peninsula, and for sponsoring Christopher Columbus's 1492 voyage, leading to the discovery of the Americas. Aragon was a significant medieval kingdom in northeastern Spain, known for its cultural and political influence. The union of Aragon and Castile under Isabella and Ferdinand laid the foundation for modern Spain, establishing a powerful monarchy that would shape European history.