William went back to Normandy in spring 1067. He took with him Edgar Aethling, Earl Edwin, Earl Morcar and Earl Waltheof.
When he came back in December, Norman control was under threat. In 1068, Edwin and Morcar fled north and began a rebellion against William. They went north, where they were joined by others including Edgar, Waltheof and Gospatric.
William and his forces headed north, building castles as they went.
When William took control of Warwick, Edwin and Morcar surrendered.
William pardoned Edwin and Morcar, but kept them as ‘guests’ at his court.
Edgar and other rebels fled to Scotland, creating a new centre of resistance there.
William’s strength would have convinced many that further revolt was useless.
Edwin and Morcar may just have been testing William’s response – this would explain why they surrendered so quickly.