There were no lack of motives, any of which would have been temptation enough for invasion. To the pious it took on the alluring guise of a Crusade. The Irish Church, which had obtained such glowing fame in its early days, had long since, as we have seen, grown into very bad repute with Rome. Despite that halo of early sanctity, she was held to be seriously tainted with heresy. She allowed bishops to be irregularly multiplied, and consecrated contrary to the Roman rule by one bishop only; tithes and firstfruits were not collected with any regularity; above all, the collection of Peter's pence, being the sum of one penny due from every household, was always scandalously in arrears, nay, often no attempt was made to collect it at all. She did many wrong things, but it may shrewdly be suspected that this was one of the very worst of them.
It is not a little edifying at this juncture to find the Danes of Dublin amongst those who were enlisted upon the orthodox side. Cut off by mutual hatred rather than theological differences from the Church of Ireland, they had for some time back been regularly applying to Canterbury for their supply of priests. These priests upon being sent over painted the condition of Irish heterodoxy in tints of the deepest black for their own
countrymen. Even before this there had been grave complaints. Lanfranc, Anselm, St. Bernard of Clairvaux, all had had their theological ire aroused against the Irish recusants. Many of the Irish ecclesiastics themselves seem to have desired that closer union with Rome, which could only be brought about by bringing Ireland under the power of a sworn son of the Church. Henry I--little as that most secular-minded of monarchs cared probably for the more purely theological question--was fully alive to its value as supporting his own claims. He obtained from Pope Hadrian IV. (the Englishman Brakespeare), a Bull sanctioning and approving of the conquest of Ireland as prompted by "the ardour of faith and love of religion," in which Bull he is desired to enter the island and therein execute "whatever shall pertain to the honour of God, and the welfare of the land."
Fourteen years elapsed before the enterprise thus warmly commended was carried into effect. The story of Dermot McMurrough, king of Leinster, and his part in the invasion, has often been told, and does not, I think, need dwelling upon at any great length. He was a brutal, violent-tempered savage, detested in his own country, and especially by his unfortunate subjects in Leinster. How he foully wronged the honour of O'Rorke, a chieftain of Connaught; how, for this and other offences, he was upon the accession of Roderick O'Connor driven away from Ireland; how he fled to England to do homage to Henry, and seek his protection; how, finding him gone to Aquitaine, he followed him there, and in return for his vows of allegiance received letters authorizing the king's subjects to enlist if they choose for the Irish service; how armed with these he went to Wales, and there succeeded in recruiting a band of mixed Norman and Norman-Welsh adventurers--all this is recorded at large in the histories.
Of the recruits thus enlisted, the most important was Robert de Clair, Earl of Pembroke and Chepstow, nicknamed by his contemporaries, Strongbow, whom Dermot met at Bristol, and won over by a double bribe--the hand, namely, of his daughter Eva, and the succession to the sovereignty of Leinster--a succession which, upon the Irish mode of election, he had, it may be observed, no shadow of right to dispose of.
Giraldus, who seems to have been himself in Wales at the time, speaks sentimentally of the unfortunate exile, and describes him inhaling the scent of his beloved country from the Welsh coast, and feasting his eyes tenderly upon his own land: "Although the distance," he more prosaically adds, "being very great, it was difficult to distinguish mountains from clouds." As a matter of fact, Dermot McMurrough, we may be sure, was not the person to do anything of the sort. He was simply hungry--as a wild beast or a savage is hungry--for revenge, and would have plunged into any number of perjuries, or have bound himself to give away any amount of property he had no right to dispose of in order to get it. He could safely trust, too, he knew, to the ignorance of his new allies as to what was or was not a legal transfer in Ireland.