French duchies were regions in France that were ruled by a duke or duchess. These territories were often granted by the king and held significant power and autonomy during the medieval period. The most notable duchies included Duchy of Normandy, Duchy of Brittany, and Duchy of Burgundy, each playing a crucial role in the political landscape of France. Duchies were important for their economic resources and military strength. They often had their own laws and customs, which allowed them to operate independently to some extent. Over time, many duchies were absorbed into the French crown, leading to a more centralized state.