The Emperor, Henry IV., besides openly giving all his vassals permission to embark in this expedition, which so much engaged the attention of Europe, promised his protection to the duchy of Normandy during the absence of the prince, and thereby enabled him to employ his whole force in the invasion of England [l]. But the most important ally whom William gained by his negotiations was the pope, who had a mighty influence over the ancient barons, no less devout in their religious principles, than valorous in their military enterprises. The Roman pontiff, after an insensible progress, during several ages of darkness and ignorance, began now to lift his head openly above all the princes of Europe; to assume the office of a mediator, or even an arbiter, in the quarrels of the greatest monarchs; to interpose in all secular affairs; and to obtrude his dictates as sovereign laws on his obsequious disciples. It was a sufficient motive to Alexander II., the reigning pope, for embracing William’s quarrel, that he alone had made an appeal to his tribunal, and rendered him umpire of the dispute between him and Harold; but there were other advantages which that pontiff foresaw must result from the conquest of England by the Norman arms. That kingdom, though at first converted by Romish missionaries, though it had afterwards advanced some farther steps towards subjection to Rome, maintained still a considerable independence in its ecclesiastical administration; and forming a world within itself, entirely separated from the rest of Europe, it had hitherto proved inaccessible to those exorbitant claims which supported the grandeur of the papacy. Alexander therefore hoped, that the French and Norman barons, if successful in their enterprise, might import into that country a more devoted reverence to the holy see, and bring the English churches to a nearer conformity with those of the continent. He declared immediately in favour of William’s claim; pronounced Harold a perjured usurper; denounced excommunication against him and his adherents; and the more to encourage the Duke of Normandy in his enterprise, he sent him a consecrated banner, and a ring with one of St. Peter’s hairs in it [m]. Thus were al1 the ambition and violence of that invasion covered over safely with the broad mantle of religion. [FN [l] Gul. Pict. p. 198. [m] Baker, p. 22. edit. 1684.]