The Mathesons were granted lands by the Celtic Earls of Ross and settled around Loch Alsh, Lochcarron and Kintail. In 1262 a Scottish army led by Alexander III of Scotland invaded the Isle of Skye in order to free the isles from the kings of Norway and one of the leaders of this expedition is recorded as "Kjarnac" or "Cormac Macmaghan". Following the Battle of Largs in 1263 the Western Isles came to be dominated by the Clan Donald whose chiefs were the Lords of the Isles and the Clan Matheson sided with them.