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 the Conqueror Norman cavalry. During the Bretons' flight, rumours swept through the Norman forces that the duke had been killed, but William succeeded in rallying his troops. Two further Norman retreats were feigned, to once again draw the English into pursuit and expose them to repeated attacks by the Norman cavalry. The available sources are more confused about events in the afternoon, but it appears that the decisive event was Harold's death, about which differing stories are told. William of Jumièges claimed that Harold was killed by the duke. The Bayeux Tapestry has been claimed to show Harold's death by an arrow