The House of Aragon was a royal dynasty that originated in the Kingdom of Aragon, located in northeastern Spain. It played a significant role in the history of Spain and Europe from the 11th century onwards. The house is known for its influential monarchs, including Ferdinand II of Aragon, who united Spain through his marriage to Isabella I of Castile. The House of Aragon expanded its influence through strategic marriages and conquests, leading to the establishment of a vast empire that included territories in Italy, Sicily, and the Mediterranean. Its legacy includes contributions to culture, politics, and the spread of Christianity during the Reconquista.