Throughout most of 800 years, Somerled of Argyll has been variously denounced as an intractable rebel against his rightful king and esteemed as the honoured ancestor of the later medieval Lords of the Isles, but he can be recognized as a much more complex figure of major prominence in 12th-century Scotland and of truly landmark significance in the long history of the Gael. The author assembles, evaluates and interprets the full spectrum of evidence - from Scottish and Manx chroniclers, Irish annalists and Gaelic tradition bearers - for Somerled's life and legend. Individual chapters investigate his emergence in the forefront of the Gaelic-Norse aristocracy of the western seaboard, his part in Gaeldom's challenge to the Canmore kings of Scots, and his extraordinary invasion of the Clyde which was cut short by his violent death at Renfrew in 1164.