William on his deathbed in 1087 decided how his sons would inherit the lands of his native Normandy and recently conquered England. His eldest son Robert was made Duke of Normandy and his third eldest son William Rufus was made King of England. This came to pass on William's death. The division of William the Conqueror's lands into two parts presented a dilemma for those nobles who held land on both sides of the English Channel. Since the younger William and his brother Robert were natural rivals, these nobles worried that they could not hope to please both of their lords, and thus ran the risk of losing the favour of one ruler or the other, or both. The only solution, as they saw it, was to unite England and Normandy once more under one ruler. The pursuit of this aim led them to revolt against William in favour of Robert, under the leadership of the powerful Bishop Odo of Bayeux, who was a half-brother of William the Conqueror. The rebels, led by William the Conqueror's half-brothers Odo of Bayeux and Robert, Count of Mortain, with Odo the stronger of the two and the leader, decided to band together to dispose of young King William II and reunite Normandy and England under a single ruler, Robert. Among King William's initial supporters were all the bishops of England, a few major magnates including Alan Rufus, William of Coutances, to Norfolk with Roger Bigod, Roger of Montgomery at Shrewsbury in Shropshire, and a vast swathe of territory in the south-west, centre and south of England under Count Robert. In support of the rebels were Eustace III, Count of Boulogne and "Hugh de Grantmesnil, who had the government of Leicestershire, with Robert de Rhuddlan his nephew, and other knights of distinguished bravery".
The rebellion
With the coming of summer in 1088, the barons set out on a campaign to lay waste the lands of William II and his supporters. They fortified their own castles and stocked them with provisions, and waited for a response from the king. If for some reason no response came, they knew they could easily live by plundering neighbouring territories, and thus reduce the kingdom to feudal anarchy, a situation the king would eventually have to address. The king's response was threefold. First, he divided his enemies by promising those who sided with him that they would receive as much money and land as they wanted. Second, he appealed to the English people as a whole, promising them "the best law that had ever been in this land". This had a positive effect in allowing regional garrisons the support they needed to fight the rebels. Finally, he attacked the rebels personally. In a six-week siege of Pevensey Castle in Sussex he captured the rebel leader Odo. In a stroke of luck for the king, the troops Robert was sending from Normandy were driven back by bad weather on the seas. Meanwhile, the king, together with some of his allies took Rochester Castle in Kent, and with Robert's failure to arrive, the rebels were forced to surrender and the rebellion was over. Those of William's barons who had remained loyal urged leniency for the rebel barons, Orderic Vitalis says, addressing the king: Odo, previously the richest man in England, was stripped of his belongings and banished to Normandy for life, while his nephew Robert Curthose was allowed to stay in England and keep his estates in Normandy, on the proviso that he recognise William II as king and set aside his claim to the throne. Roger of Montgomery had left the rebels and joined with the king after promises of land and money. The king pragmatically kept those aristocrats whom he needed and removed those who were a threat. William de St-Calais, Bishop of Durham, who had abandoned the king's army during the campaign, was tried later in the year, deposed, and exiled to Normandy, but in 1091 returned and was reinstated.
