The Battle of Renfrew was fought between the Kingdom of the Isles and the Kingdom of Scotland in 1164, near Renfrew, Scotland. The men of the Isles, accompanied by forces from the Kingdom of Dublin, were commanded by Somairle mac Gilla Brigte, King of the Isles. The identity of the Scottish commander is unrecorded and unknown. Herbert, Bishop of Glasgow, Baldwin, Sheriff of Lanark/Clydesdale, and Walter fitz Alan, Steward of Scotland are all possible candidates for this position. The battle was a disaster for the Islesmen and Dubliners. Somairle was slain in the encounter, apparently by local levies, and his forces were routed. Somairle first appears on record in the 1150s, when he is stated to have supported the cause of Máel Coluim mac Alasdair in a rebellion against Malcolm IV, King of Scotland. Máel Coluim was a member of a rival branch of the Scottish royal family, and his sons were closely related to Somairle. At about the time of the rebellion's collapse, Somairle appears to have shifted his energies from Scotland towards the Isles. In 1156, he wrested about half of the Kingdom of the Isles from his brother-in-law, Guðrøðr Óláfsson, King of the Isles. Two years later, Somairle decisively defeated Guðrøðr, gaining complete control of the kingdom. The reasons for Somairle's invasion of Scotland are uncertain. One possibility is that he was renewing his support for the sons of Máel Coluim. Another possibility is that he was attempting to conquer the southwest part of Scotland that may have only recently fallen under Scottish royal authority. This region had previously been occupied by the Gall Gaidheil, a people of mixed Scandinavian and Gaelic ethnicity, like Somairle himself. There is reason to suspect that this region was lost to the Scots upon the collapse of Máel Coluim's rebellion, and afterwards doled out to powerful Scottish magnates in the context of Scottish consolidation. Somairle may have also invaded the region in an attempt to counter a perceived threat that the Scots posed to his authority in the Firth of Clyde. The fact that the battle is said to have been fought at Renfrew, the seat of one of Walter's lordships, could indicate that he was a specific target. As a result of Somairle's death in battle, the Kingdom of the Isles fractured once again. Although Guðrøðr's brother, Rǫgnvaldr, is recorded to have gained power, Guðrøðr was able overcome him within