the high-kingship of Ireland, an office then held by the elderly Toirrdelbach Ua Conchobair, King of Connacht. In 1154, the forces of Toirrdelbach and Muirchertach met in a major maritime conflict off the Inishowen coast. According to the seventeenth-century Annals of the Four Masters, Muirchertach's maritime forces were mercenaries drawn from Galloway, Arran, Kintyre, Mann, and "the territories of Scotland". This record appears to be evidence that Guðrøðr, Fergus, and perhaps Somairle, provided ships to Muirchertach's cause. Although Toirrdelbach's forces obtained a narrow victory, his northern maritime power seems to have been virtually nullified by the severity of the contest, and Muirchertach soon after marched on Dublin, gained overlordship over the Dubliners, and effectively secured himself the high-kingship of Ireland for himself. The defeat of forces drawn from the Isles, and Muirchertach's subsequent spread of power into Dublin, may have had severe repercussions concerning Guðrøðr's career. In 1155 or 1156, Somairle and an apparent relative of Ottar precipitated a coup against Guðrøðr, presenting Somairle's son, Dubgall, as a replacement to Guðrøðr's rule. Late in 1156, Somairle and Guðrøðr clashed and divided the Kingdom of the Isles between themselves. Two years later the former drove the latter from the kingship and into exile. It is uncertain why Fergus failed to support his grandson against Somairle. The record of the capture of Domnall mac Máel Coluim at Whithorn in 1156, as recorded by the twelfth- to thirteenth-century Chronicle of Holyrood, and Gesta Annalia I, may have bearing on Fergus. Domnall appears to have been a son of Máel Coluim mac Alasdair, who was in turn a claimant to the Scottish throne and somehow related to Somairle. Following David's death in 1153, Somairle and Máel Coluim had risen in revolt against a newly inaugurated Malcolm without much success. Domnall's later capture in western Galloway, therefore, could be evidence that the Meic Máel Coluim claimants had attempted to forcefully carve out a power base in western Galloway. However, the fact that the chronicle makes no mention of such conflict in Galloway, coupled with the fact that Whithorn was a spiritual centre rather than a secular power centre, could suggest that Domnall was in the region under less violent circumstances. If so, it is conceivable that Fergus could have originally forged an understanding with the Meic Máel Coluim before pressure from his sons forced him to desert Domnall's cause. The fact that the latter's capture