Isabella I of Castile, known as Isabella the Catholic, redefined the trajectory of the Iberian Peninsula and the Americas. Her reign, alongside her husband Ferdinand II of Aragon, saw the completion of the Reconquista, the unification of Spain, and the sponsorship of Christopher Columbus’s voyage in 1492. These events are often documented in multi-volume series, where specific references like "45" may correspond to volume numbers or specific archival entries in Spanish historical collections. The Significance of the Title "La Catolica"