The Northern Invasion.
The news of Harold's marriage to Ealdgyth put an end to the demands of William of Normandy that Harold should take one of his daughters to wife, and in the complaints that he addressed to all Christendom against Harold the breach of his promise in this respect was placed far more prominently than his failure to carry out his oath to be the duke's man. It must have been evident indeed to all that it was beyond the power of the English king to keep this oath, obtained from him by force and treachery. He had been elected by the voice of the English people, and had no more power than the meanest of his subjects to hand the crown they had bestowed to another.

The breach of this oath, however, served to obtain all the aid that the church could give to William. Harold was solemnly excommunicated, and the struggle for which the duke was preparing thereupon assumed the character of a sacred war. In England itself the Bull of excommunication had no effect whatever. The great bulk of bishops and clergy were Englishmen, and thought far more of their king than of any foreign prince or prelate. Even the bishops and abbots of Norman blood disregarded the commination, and remained staunch to Harold. He had been a generous patron to the church, had maintained them in all the privileges and dignities that Edward had bestowed upon them, and possessed the love of the whole English people; therefore, in spite of bann and interdict the churches remained open, services were held as usual, and people were married and buried as if the Papal Bull had never been issued.