The Kingdom of Aragón was a medieval kingdom located in the northeastern part of the Iberian Peninsula. It emerged in the 9th century and became a significant political and cultural entity in the region. The kingdom expanded its territory through conquests and alliances, eventually merging with the Kingdom of Navarre and later the Crown of Aragon. Aragón played a crucial role in the formation of modern Spain, particularly through its union with the Kingdom of Castile in the late 15th century. The kingdom was known for its unique laws, customs, and a strong sense of regional identity, which influenced the development of Catalonia and Valencia.