The House of Trastámara was a royal dynasty that ruled over Spain and parts of Europe from the late 14th century to the early 16th century. It originated from the union of the Kingdom of Castile and the Kingdom of León, and its most notable monarchs include Isabella I of Castile and Ferdinand II of Aragon. Their marriage in 1469 united the two kingdoms, leading to the eventual unification of Spain. The Trastámara dynasty played a crucial role in the Spanish Reconquista, which aimed to reclaim territory from Muslim rule. Their reign also marked the beginning of Spain's global exploration, including the sponsorship of Christopher Columbus' voyages to the Americas in 1492. The dynasty ended with the death of Queen Isabella in 1504, leading to the rise of the Habsburg dynasty.