Stephen, King of England In 1138, Robert renounced his fealty to Stephen and declared his support for Matilda, triggering a major regional rebellion in Kent and across the south-west of England, although Robert himself remained in Normandy. In France, Geoffrey of Anjou took advantage of the situation by re-invading Normandy. David of Scotland also invaded the north of England once again, announcing that he was supporting the claim of his niece the Empress Matilda to the throne, pushing south into Yorkshire. Anglo-Norman warfare during the reign of Stephen was characterised by attritional military campaigns, in which commanders tried to seize key enemy castles in
Norman conquest of England had moored for the winter south of the Humber in Lincolnshire, and drove them back to the north bank. Leaving Robert of Mortain in charge of Lincolnshire, he turned west and defeated the Mercian rebels in battle at Stafford. When the Danes attempted to return to Lincolnshire, the Norman forces there again drove them back across the Humber. William advanced into Northumbria, defeating an attempt to block his crossing of the swollen River Aire at Pontefract. The Danes fled at his approach, and he occupied York. He bought off the Danes, who agreed to leave England in the spring, and