The Rebellion of 1088 occurred after the death of William the Conqueror and concerned the division of lands in England and Normandy between his two sons William Rufus and Robert Curthose. Hostilities lasted from 3 to 6 months starting around Easter of 1088.

Background

William on his death bed in 1087 wished to carry his heavily authoritarian rule beyond the grave by deciding how his sons would inherit the lands of his native Normandy and recently conquered England. His eldest son Robert was granted Duke of Normandy and his second eldest William Rufus entitled King of England. This came to pass on William's death. However, for the princes and barons who owned lands in both Normandy and England, it presented a difficult situation of loyalty. The chronicler Orderic Vitalis said of the Norman magnates:

What are we to do? Now that our lord is dead, two young men have succeeded and precipitately divided the lordship of England and Normandy. How can we properly serve two lords who are so different and distant from each other? If we serve Robert, duke of Normandy, worthily, we will offend his brother, William, and we will be stripped by him of our great revenues and large estates in England. On the other hand, if we obey king William fittingly, duke Robert will deprive us of all our inherited lands in Normandy.

They decided to band together to dispose of young king Rufus and unite Normandy and England under a single king, the young Duke Robert. The rebels were lead by William the Conqueror's elder half-brothers Odo of Bayeux and Robert, Count of Mortain, with Odo the stronger of the two and leader behind the plot.

The rebels ranks were made up of the most powerful barons in England, of the ten largest baronial landholders in the Doomsday book, six were counted amongst the rebels. They were spread far and wide geographically from Kent controlled by Odo, to Northumberland, controlled by Robert de Mowbray , to Norfolk with Roger Bigod, and the great magnate Roger of Montgomery in Shrewsbury. The rebels strategy was to assume that Robert would launch an invasion force from Normandy, and in the mean time, Odo and the rebel Barons would start the fight in England.

Rebellion of 1088

With the coming of spring in 1088, the barons set out on a campaign to lay waste to the king's lands and supporters. They then activated their own castles, fortified 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 neighboring territories and reduce the kingdom to feudal anarchy, a situation the king must eventually address.

Rufus's response was three part. First he divided his enemies by promising those who sided with the king 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 he captured the rebel leader Odo.

In a stroke of luck for Rufus, the troops Robert was sending from Normandy were driven back by bad weather on the seas. Meanwhile Rufus took Rochester Castle, and with the failure of Robert to arrive, the rebels were forced to surrender and the rebellion was over.

William's barons who had remained loyal urged leniency on the rebel barons. Orderic Vitalis says of the king:

..if you remit your anger against these men [the rebels] and benevolently retain them with you, or at least allow them to depart in peace, you will enjoy the benefits of their friendship and service on many future occasions. It may be that the man who harms you, later obeys you as a friend.

Odo, previously the richest man in England, was stripped of his belongings and banished to Normandy, while his brother Robert of Mortain was allowed to stay in England and keep his estates. Robert de Mowbray was imprisoned for life. Roger of Montgomery had left the rebels and joined with the king after promises of land and money. William pragmatically kept those aristocrats who he needed and removed those who were a threat.