Malachi’s triumph, however, was gained at the cost of a disruption of the monarchy. Malachi himself was displaced by a king of the rival house of Munster, his colleague in the sack of Dublin, the famous Brian Boroimhe;[377] Brian’s career of conquest ended in 1014 on the field of Clontarf, where he was slain in battle with the men of Leinster and the Ostmen;[378] and when Malachi, who now resumed his place, died in 1022,[379] the downfall of the Irish monarchy was complete.[380] The tradition which had so long linked it to the house of Niall had been shattered by Brian’s successes; and Brian had not lived to consolidate in his own house the forces which had begun to gather around himself. Thenceforth the Scandinavian colonies simply furnished an additional element to the strife of the Irish chieftains, and to the rivalry between the O’Briens of Munster and the O’Neills of Ulster for the possession of a shadowy supremacy, claimed by the one house as descendants of Brian Boroimhe and by the other as heirs of Malachi II. and of his great ancestor Niall. [377] Tighernach, a. 1000, 1001 (as above, pp. 269, 270). _Wars of Gaedhil with Gaill_ (Todd), p. 119. Brian’s victory was won by the help of the Ostmen, with whom he stooped to ally himself for the sake of overcoming his rival; but the alliance was only momentary. On Brian’s reign see _Wars of Gaedhil with Gaill_, pp. 119–155. [378] _Wars of Gaedhil with Gaill_ (Todd), pp. 155–211. Four Masters, a. 1013 (O’Donovan, vol. ii. pp. 773–781). Ann. Loch Cé, a. 1014 (Hennessy, vol. i. pp. 1–13). [379] Tighernach, a. 1022 (as above, p. 274). Four Masters, a. 1022 (as above, p. 800). Ann. Loch Cé, a. 1022 (as above, p. 23). [380] “From the death of Maelseachlainn II. the legitimate monarchy of all Ireland departed from all families during seventy-two years, until the joint reigns of Muircheartach O’Briain and Domhnall MacLochlainn; during that time no Feis or general assembly, so agreeable to the people, was held, because Ireland had no supreme king.” Quoted by Mr. Kelly, note to _Cambrensis Eversus_, vol. ii. p. 38, from Gilla-Modud, an Irish poet of the twelfth century.