Although we can scarcely speak of a Reformation in Ireland, we may briefly notice the changes in her ecclesiastical history. The connection of Ireland with the crown of England originated, as we have already seen, in a compact with Henry II., Pope Adrian IV., and the Irish prelates of the day. "This treaty," says Dr. Phelan, "would be memorable, if it had no other claim to the consideration of posterity than the hypocrisy, the injustice, and the mutual treachery of the parties; but their views and pretensions, descending regularly to their successors, and exerting a constant influence on Irish affairs, make it an object of nearer interest. Without attention to these, it is impossible either to unravel the history of Ireland, or to judge correctly of its state at the present crisis." "The acquisition of a superiority by Henry over Ireland was greatly aided," says Mosheim, "by a desire of the national hierarchy to attain that independent and prosperous condition, which was then common to all clerical communities closely connected with Rome." Thus was the position of the bishops greatly improved, and their revenues increased, though at the high price of the independence of their nation.
In 1172 Henry completed his conquest of the country; the clergy submitted to the papal dictation, agreed to pay Peter's pence to Rome, proclaimed Henry's title to the sovereign dominion of Ireland, and took the oath of fidelity to himself and his successors. "Adrian's sentence," says a friend of Romanism, "violated the rights of nations, and the most sacred laws of men, under the special pretext of religion and Reformation. Ireland was blotted out from the map of nations, and consigned to the loss of freedom without a tribunal and without a crime." The hierarch, however, did not regret the change. Hitherto, the native chieftains had exercised a power over the church, which tended to keep its clergy poor and subservient; so that they welcomed the sovereignty of England and the power of Rome as protection against the ravages of their lay-lords.
"Under the ancient system, an Irish prince was as absolute master of the priesthood as of any other class among his followers. But a new order of things was introduced by Henry II., and thenceforward kept regular pace with the advance of British and papal power. All the privileges of the English church, and all those vexatious pretensions, which had just attained a temporary triumph in the canonization of Thomas-a-Becket, were communicated to the Irish clergy, and maintained by them with more pertinacity, in proportion to the weakness of the civil power." From this period the Irish church came to be essentially Romish, the papal encroachments were tamely submitted to, and both the civil and spiritual rights of the Irish prelates were at the entire disposal of the Roman pontiff. Henry, in order to maintain his sovereignty over the Irish clergy, filled up the vacant sees mostly with Englishmen, and the consequence was, that a spirit of jealousy and bitter hostility began to be manifested between the English and the Irish ecclesiastics. Disputes arose; the English sovereign asserted his privilege in nominating whom he would; the Irish clergy, meanwhile, appealed to Rome to decide the question, or rather, to confirm their nomination. The miter usually prevailed over the crown, and the pope's authority steadily increased.
Thus the contest between the English sovereigns and the Irish clergy commenced; the latter sought to transfer their allegiance as churchmen from the sovereign of England to the pope of Rome, so that the struggle for supremacy lasted for centuries, even until the era of the Reformation.