Henry I of France whose death Henry was left to deal with his rebel sibling. In 1032, he placated his brother by giving him the duchy of Burgundy which his father had given him in 1016. In an early strategic move, Henry came to the rescue of his very young nephew-in-law, the newly appointed Duke William of Normandy (who would go on to become William the Conqueror), to suppress a revolt by William's vassals. In 1047, Henry secured the dukedom for William in their decisive victory over the vassals at the Battle of Val-ès-Dunes near Caen; however, Henry would later support the barons against
William III, Duke of Aquitaine William III, Duke of Aquitaine William III (915 – 3 April 963), called Towhead (, ) from the colour of his hair, was the "Count of the Duchy of Aquitaine" from 959 and Duke of Aquitaine from 962 to his death. He was also the Count of Poitou (as William I) from 935 and Count of Auvergne from 950. The primary sources for his reign are Ademar of Chabannes, Dudo of Saint-Quentin, and William of Jumièges. William was son of Ebalus Manzer and Emilienne. He was born in Poitiers. He claimed the Duchy of Aquitaine from his father's death, but