Some time around 839, the Norse Vikings inflicted a crushing defeat on the kings of the Picts and Dalriada, both of whom were slain in the battle. Dalriada, which had extended over Scotland’s western coasts and islands, was eventually annexed into the Norse earldom of Orkney. In the immediate aftermath there was period of interregnum, followed by Kenneth MacAlpine (843–858) seizing tenuous control of Alba, although Cumbria remained an independent kingdom ruled from Dumbarton. There followed a succession of short-lived kings, most of whom met violent ends, before Constantine II (900–43), joined Vikings, Welsh and Cumbrians to invade England, only to be comprehensively defeated by Saxon king Athelstan at Brunanburh (937). Constantine’s son, Malcolm I, wisely switched to the Saxon side at Dunmail Raise (945), receiving Cumbria as his reward. Malcolm II would, through victory at Carham (1018), annex Lothian from the earldom of Northumbria.
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