The Duke of Brittany was a title held by the rulers of the historical region of Brittany in northwestern France. This title emerged in the 9th century and was significant in the political landscape of medieval France. The dukes played a crucial role in the region's autonomy and its cultural identity, often navigating complex relationships with the French crown. The title of Duke of Brittany was officially abolished in 1532 when Brittany was united with France. However, the legacy of the dukes remains influential in Brittany's culture and history, with many historical sites and traditions still celebrated today.