The Duchy of Aquitaine was a significant medieval territory in southwestern France, established in the 9th century. It became a powerful duchy, known for its wealth and cultural influence, particularly during the reign of Eleanor of Aquitaine, who married both Louis VII of France and Henry II of England. Aquitaine played a crucial role in the political landscape of medieval Europe, often changing hands between French and English rulers. The duchy was known for its distinct regional identity, language, and customs, contributing to the rich tapestry of French history and the Plantagenet dynasty.