Prior to the 1266 Treaty of Perth, the Western Isles of Scotland were controlled by various Norse and Gaelic rulers who owed their allegiance to the Kings of Norway rather than the kings of Scotland.

The events are recorded in "Sverris Saga," one of the "King's Sagas," or prose poems, written in Norway and Iceland between the 12th and 14th centuries to glorify Norse kings. Study co-author ...