[Note 1] At times the rulers were independent of external control, although for much of the period they had overlords in Norway, Ireland, England, Scotland or Orkney.
Hostility between the Kings of the Isles and the rulers of Ireland, and intervention by the crown of Norway (either directly or through their vassals the Earls of Orkney) were recurring themes.
[27] Eiríkr is believed by some authorities to be synonymous with the saga character Eric Bloodaxe, although the connection is questioned by Downham (2007), who argues that the former was an Uí Ímair dynast rather than a son of Harald Fairhair.
[28] A raid on Northumbria in 949, the purpose of which may have been either to support or oppose the kingship of Amlaíb Cuarán is described as predam albidosorum idem nannindisi in the Chronicle of the Kings of Alba.
The island has produced a more densely distributed Viking Age archaeology than anywhere else in the British Isles, but the written records for this time period are poor.
[69] Indech is also mentioned in the Cath Maige Tuired along with Balor grandson of Nét, his rival who is described as righ na n-Innsi ('king of the Isles'), which may have meant the king of the Inner Hebrides.
"[70] Various later rulers such as Gebeachan are also mentioned in early sources as having a role of some kind over unspecified areas of the northern part of the Kingdom of the Isles.
Godred the Black's dictatorial style appears to have made him very unpopular with the Islesmen, and the powerful barons of the isles began plotting with an emerging and forceful figure – Somerled, Lord of Argyll.
Two years later Somerled's invasion of the Isle of Man caused Godred to flee to Norway, leaving the former as the undisputed ruler of the entire realm.
The Chronicle of Man and the Sudreys lamented that Somerled's marriage to Ragnhildis, daughter of Olave the Red, had been "the cause of the ruin of the whole kingdom of the Isles".
"[102] Norse sources also refer to kingship being held by Eóghan of Argyll,[103] although this was rescinded by King Haakon when he refused to participate in the latter's expeditions against Scotland.