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 feudal system, representing both political power and territorial control. The dukes played a crucial role in the region's history, often navigating complex relationships with the French crown. The title of Duke of Brittany was officially abolished in the late 16th century when Brittany was integrated into the Kingdom of France. However, the legacy of the dukes remains influential in Brittany's cultural identity, with many historical sites and traditions still celebrated today.