The Irish Church long continued to keep Easter on a different day from that sanctioned by Rome, and to use a different form of tonsure. But the inconvenience of such dissidence from the general body of Western Christendom was soon felt. About 630 Pope Honorius I. addressed a letter to the Irish Church, in which he reminded the clergy that they were a scanty company inhabiting a remote region, and that it could not be for their interest to remain isolated. Cummian, afterwards seventh abbot of Iona, warmly espoused the papal cause. 'Rome errs,' he said with great scorn, 'Jerusalem errs, Alexandria errs, Antioch errs, the whole world errs--the Britons and Irish are the only right-minded people.' The southern Irish followed Cummian, but the northern rejected his advice, and some even called him a heretic; yet this did not prevent his being elected to fill Columba's chair. Adamnan, ninth abbot of Iona, and biographer of the great founder, was no less earnest on the Roman side than Cummian had been. At the Synod of Whitby in 664 Wilfred discomfited Colman of Lindisfarne, and settled the question so far as England was concerned. Adamnan lived till 704, and succeeded in converting nearly all the Irish churches, except those subject to his own monastery. [Sidenote: Close of the Paschal controversy, 716.] In 716, under Duncadh, the eleventh abbot, Iona conformed, and the Paschal controversy came to an end, after lasting 150 years. The coronal tonsure was adopted three years later. The supremacy of Rome was thus acknowledged, but circumstances long prevented the Irish from adopting the Roman plan of Church organisation. [Sidenote: Influence of the Scandinavian invasions on the Church.] [Sidenote: The Eugenian Constitution, 1151.]