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 household departments. William cultivated close relations with the church in his duchy. He took part in church councils and made several appointments to the Norman episcopate, including the appointment of Maurilius as Archbishop of Rouen. Another important appointment was that of William's half-brother Odo as Bishop of Bayeux in either 1049 or 1050. He also relied on the clergy for advice, including Lanfranc, a non-Norman who rose to become one of William's prominent ecclesiastical advisors in the late 1040s and remained so throughout the 1050s and 1060s. William gave generously to the church; from 1035 to 1066, the Norman aristocracy