Hoel I, Duke of Brittany was a prominent figure in the medieval period, ruling from around 1040 until his death in 1084. He was a member of the House of Rennes and played a significant role in the political landscape of Brittany, a region in northwestern France. His reign was marked by efforts to strengthen the duchy and maintain its independence from external influences. During his rule, Hoel I worked to consolidate power and foster alliances, particularly with the Normans and the Kingdom of England. He is often remembered for his contributions to the development of Brittany's governance and for navigating the complexities of feudal relationships in a turbulent era.