Note 433 — Chapter III · THE CONQUEST OF IRELAND. 795–1172.

Four Masters, a. 1152 (O’Donovan, vol. ii. p. 1103). Cf. Gir. Cambr., Expugn. Hibern., l. i. c. 1 (Dimock, vol. v. pp. 225, 226), and the elaborately romantic account in the Anglo-Norman Poem on the Conquest of Ireland, edited by M. Francisque Michel, pp. 2–6. The two last-named authorities represent this affair as the immediate cause of Dermot’s overthrow, and of all the consequent troubles. Chronology shews this to be mere romance; yet, notwithstanding the criticisms of some modern writers, there still seems to be some ground for the earlier view which looked upon Dervorgil as a sort of Irish Helen. If we follow carefully the thread of the story in the Four Masters from 1153 to 1166 we can hardly avoid the conclusion that throughout those years the most important personage in Irish politics, the man whose action turned the scale in nearly all the ups and downs of fortune between Murtogh of Ulster and the kings of Connaught, was the border-chieftain whose position made him the most dangerous of foes and the most indispensable of allies—Tighernan O’Ruark; and we can hardly help seeing in Dermot’s banishment the vengeance less of Roderic O’Conor himself than of a supporter whom Roderic could not afford to leave unsatisfied. On the other hand, it is perfectly true that the opportunity for executing that vengeance was given by the disaffection of Dermot’s own subjects—and, as usual, more especially by the rising of the Ostmen of Dublin.