The Kingdom of Aragon was a medieval kingdom located in the northeastern part of the Iberian Peninsula. It emerged in the 11th century and became a significant political and cultural entity in the region. The kingdom expanded its territory through conquests and alliances, eventually incorporating parts of modern-day Spain and France. Aragon played a crucial role in the Reconquista, the effort to reclaim the Iberian Peninsula from Muslim rule. In 1469, the marriage of Ferdinand II of Aragon and Isabella I of Castile united the two kingdoms, leading to the formation of a powerful Spanish state. This union marked the beginning of a new era in Spanish history.