Born c.1113 in Morvern, Argyll, Somerled was half-Norse through his mother. His father's lineage was reputedly of royal blood. Forced into exile in Ireland his family convinced the Colla clan to help them reclaim their Argyll lands, but his father was killed in the attempt. Growing up and living as a warrior hermit, Somerled led the inhabitants of Morvern against the Norse and regained his family's lands thus becoming master of large tracts of northern Argyll. Soon after, he took control of the south of Argyll and pronounced himself Thane of Argyll. At the same time, King David I was waging war against the Norwegians and Somerled's stature and currency rose with the king accordingly. Somerled wooed King Olaf the Red by marrying his daughter c.1140. For 14 years they lived in relative peace until Olaf was murdered by his nephews who siezed control of the Norse lands in the Hebrides. Olaf's son Godfrey, a tyrant, reclaimed these lands but the inhabitants revolted and appealed to Somerled who then led a successful resistance and took Argyll in its entirety.
Somerled's invention of the moveable stern rudder gave his sailors an advantage over the Norse war galleys and when Godfrey and Somerled clashed again two years later the Norse galleys were routed. Somerled became King of the Isles around 1156 but was able to treaty with King Malcolm IV who was concerned at Somerled's increasing power. However, after being insulted by Malcolm once too often, Somerled invaded the Clyde in 1163 with 164 galleys and 15,000 men and marched on Renfrew. What happened next is unclear but Somerled died in 1164 and his army dispersed back to the isles. His legacy was in fathering the Clan Donald, the creation of the finest galleys ever seen in Scottish waters and the enduring power base of the Lordship of the Isles.