The Crown of Aragon was a medieval kingdom in the northeastern part of the Iberian Peninsula, established in the 11th century. It originated from the County of Aragon and expanded to include regions such as Catalonia, Valencia, and the Balearic Islands. The crown played a significant role in the political and cultural development of Spain. The Crown of Aragon was known for its maritime power and trade, particularly in the Mediterranean. It became a major player in the Reconquista, the effort to reclaim territory from Muslim rule. The union with the Crown of Castile in 1469 marked the beginning of a unified Spain.