Stephen, King of England began to influence the loyalty of many Anglo-Norman barons, who feared losing their lands in England to Robert and the Empress, and their possessions in Normandy to Geoffrey. Many started to leave Stephen's faction. His friend and advisor Waleran was one of those who decided to defect in mid-1141, crossing into Normandy to secure his ancestral possessions by allying himself with the Angevins, and bringing Worcestershire into the Empress's camp. Waleran's twin brother, Robert of Leicester, effectively withdrew from fighting in the conflict at the same time. Other supporters of the Empress were restored in their former strongholds, such as
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