A Norse-Gaelic sea-kingdom uniting the Hebrides, the Firth of Clyde islands, and the Isle of Man under Viking and later mixed Norse-Gaelic rulers (the Uí Ímair and, from the 12th century, the Crovan dynasty of 'Kings of Mann and the Isles').
Ceded by Norway to Scotland under the 1266 Treaty of Perth, following Norway's defeat at the Battle of Largs (1263), ending Norwegian overlordship of the Isles.
The atlas holds 6 border frames for Kingdom of the Isles — the shape you scrub through changes in 900 · 1140 · 1161 · 1190 · 1215 · 1246.
The standard dedicated academic history of exactly this polity.