The battle of Brunanburh had probably left Strathclyde even more vulnerable that the kingdom of the Scots. In 945 Athelstan's successor, Edmund, 'laid waste the land of the Cumbrians' but, according to the Anglo-Saxon Chronicle, he then 'granted it all to Malcolm, King of Scots', who had succeeded when Constantine retreated into the holy life in 943. This recognition by Wessex of the overlordship long exercised by kings of Scots over Strathclyde clarified the ambiguities in the treaty concluded between Constantine and Edward the Elder of Wessex in 920, which had seemed incidentally to grant the Scots an interest in Strathclyde in return for non-interference in the affairs of York. The confusion into which the York kingdom fell between the assassination of Edmund in 946 and the arrival of a new, ruthless claimant in the formidable shape of the Norwegian king, Eirik Bloodaxe in 947, twice installed and twice removed in the space of the next five years, brought to a head another crisis in the intricate quadrille performed around the vulnerable York kingdom by kings of Scots, Wessex, and two sets of rival Scandinavian interests.

Between 948 and 952 Eirik Bloodaxe had brooded in exile on Orkney. His presence there could only have reinforced the insecurity felt by Malcolm I at the prospect of being encircled by hostile Norwegian interests, based not only in York but also in Caithness and the Northern Isles. It is no coincidence that Malcolm was the first of the mac Alpin kings to attempt to expand his authority north of the Spey. His success was modest: on victory somewhere in Moray against Cellach, who was probably mormaer of that province. His successors were no more effective.

It may be doubted whether Malcolm himself was killed in Moray rather than by the men of the Mearns in 954, but his son Dubh was certainly overthrown in the hostile territory across the Mounth in Moray in 966. Kenneth II in turn failed to make any impression against Sigurd, the Norwegian Earl of Orkney or to contest his annexation of Caithness; by 989 Sigurd the Stout seems to have extended his control further south, into Moray. Neither Kenneth III (997-1005) nor Malcolm II (1005-34) possessed the means or authority in the north to check this powerful Earl of Orkeny. Malcolm acknowledged as much by agreeing to an arranged marriage to Sigurd c. 1008. It is unclear from the source - the Orkeyinga Saga, at once verbose and sparing with the facts - whether the bride was the daughter of Malcolm himself or of Malcolm, son of Maelbigte and mormaer of Moray; this saga of the earls of Orkney might well not have bothered to discriminate between a 'king of Scots' and a provincial king of Moray. At least in this case the prospective husband was a recent convert to Christianity. By the time of Sigurd's death, at Clontarf in 1014, the boundary between the earls of Orkney and kings of Scots lay at the Moray Firth or perhaps even further south.