for revolting was that the proposed marriage between himself and one of William's daughters had not taken place, but another reason probably included the increasing power of fitzOsbern in Herefordshire, which affected Edwin's power within his own earldom. The king marched through Edwin's lands and built Warwick Castle. Edwin and Morcar submitted, but William continued on to York, building York and Nottingham Castles before returning south. On his southbound journey, he began constructing Lincoln, Huntingdon, and Cambridge Castles. William placed supporters in charge of these new fortifications – among them William Peverel at Nottingham and Henry de Beaumont at Warwick. Then the king returned to Normandy late in 1068. Early in 1069, Edgar the Ætheling rose in revolt and attacked York. Although William returned to York and built another castle, Edgar remained free, and in the autumn he joined up with King Sweyn. The Danish king had brought a large fleet to England and attacked not only York but Exeter and Shrewsbury. York was captured by the combined forces of Edgar and Sweyn. Edgar was proclaimed king by his supporters. William responded swiftly, ignoring a continental revolt in Maine, and symbolically wore his crown in the ruins of York on Christmas Day 1069. He then proceeded to buy off the Danes. He marched to the River Tees, ravaging the countryside as he went. Edgar, having lost much of his support, fled to Scotland, where King Malcolm III was married to Edgar's sister Margaret. Waltheof, who had joined the revolt, submitted, along with Gospatric, and both were allowed to retain their lands. But William was not finished; he marched over the Pennines during the winter and defeated the remaining rebels at Shrewsbury before building Chester and Stafford Castles. This campaign, which included the burning and destruction of part of the countryside that the royal forces marched through, is usually known as the "Harrying of the North"; it was over by April 1070, when William wore his crown ceremonially for Easter at Winchester. Church affairs While at Winchester in 1070, William met with three papal legates – John Minutus, Peter, and Ermenfrid of Sion – who had been sent by the pope. The legates ceremonially crowned William during the Easter court. The historian David Bates sees this coronation as the ceremonial papal "seal of approval" for William's conquest. The legates and the king then proceeded to hold a series of ecclesiastical councils