Kingdom of the Isles

The Kingdom of the Isles was a Norse-Gaelic kingdom that included the Isle of Man, the Hebrides, and the islands of the Clyde from the 9th to the 13th centuries CE. Known to the Norse as the Suðreyjar (Southern Isles), distinct from the Norðreyjar (Northern Isles of Orkney and Shetland), it is referred to in Scottish Gaelic as Rìoghachd nan Eilean. The kingdom's extent and control varied, with rulers often subject to overlords in Norway, Ireland, England, Scotland, or Orkney, and at times, the territory had competing claims.

Before Viking incursions, the southern Hebrides were part of the Gaelic kingdom of Dál Riata, while the Inner and Outer Hebrides were nominally under Pictish control. Viking influence began in the late 8th century with repeated raids, and by the 9th century, the first references to the Gallgáedil (foreign Gaels of mixed Scandinavian-Celtic descent) appear.

In 872, Harald Fairhair became the king of a united Norway, driving many of his opponents to flee to the Scottish islands. Harald incorporated the Northern Isles into his kingdom by 875 and, shortly after, the Hebrides as well. Local Viking chieftains rebelled, but Harald sent Ketill Flatnose to subdue them. Ketill then declared himself King of the Isles, though his successors remain poorly recorded.

In 870, Amlaíb Conung and Ímar besieged Dumbarton and likely established Scandinavian dominance on Scotland’s western coasts. Subsequent Norse hegemony saw the Isle of Man taken by 877. After Viking expulsions from Dublin in 902, internecine conflicts continued, such as Ragnall ua Ímair's naval battles off the Isle of Man.

The 10th century saw obscured records, with notable rulers like Amlaíb Cuarán and Maccus mac Arailt controlling the isles. In the mid-11th century, Godred Crovan established control over the Isle of Man after the Battle of Stamford Bridge. His rule marked the beginning of his descendants' dominance in Mann and the Isles, despite intermittent conflicts and rival claims.

By the late 11th century, Norwegian king Magnus Barefoot reasserted direct Norwegian control over the isles, consolidating territories through campaigns across the Hebrides and into Ireland. After Magnus's death in 1103, his appointed rulers, like Lagmann Godredsson, faced rebellions and shifting allegiances.

Somerled, Lord of Argyll, emerged in the mid-12th century as a powerful figure opposing Godred the Black's rule. Following naval battles and territorial agreements, Somerled's control expanded, effectively recreating Dalriada in the southern Hebrides. After Somerled's death in 1164, his descendants, known as the Lords of the Isles, divided his territories among his sons, leading to further fragmentation.

The Scottish Crown, seeking control over the islands, led to conflicts culminating in the Treaty of Perth in 1266, wherein Norway ceded the Hebrides and Mann to Scotland. The last Norse king of Mann, Magnus Olafsson, ruled until 1265, after which the kingdom was absorbed into Scotland.