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
Companions of William the Conqueror troop which he commanded on the right wing he attacked with the utmost bravery and success." "With a harsh voice he (Duke William) called to Eustace of Boulogne, who with 50 knights was turning in flight and was about to give the signal for retreat. This man came up to the Duke and said in his ear that he ought to retire since he would court death if he went forward. But at the very moment when he uttered the words Eustace was struck between the shoulders with such force that blood gushed out from his mouth and nose and