The early years of the reign of Malcolm II, which witnessed a renewal by him of raids into Northumbria, including a siege of Durham, must indicate that sometime in the intervening period there had been both an expansion and the contraction of the southern frontier. Both the invasion by Malcolm I, who had reached as far south as the Tees in 949, and the two extended raids by Kenneth II in the 970s, one as far south as Stainmore, were probably parts of a renewed attempt to lay claim not simply to Lothian and the Merse (Berwickshire) but to Bernicia, stretching form the Forth to the Tees. Only the first of these two issues - control of Lothian and the Merse and overlordship, nominal or otherwise, of Bernicia - was settled in this period. Edgar, King of Wessex, had conceded the fact of the virtual Scottish occupation of Lothian in 973 and Malcolm II's victory in 1018 at Carham, immediately to the south of Tweed, had merely turned occupation into annexation. Yet 1018, so often fastened upon as marking the firm delineation of a southern frontier along the line of the Tweed, could not have seemed so decisive or final a victory at the time. Rather than settling the Lothian question, it raised again the unresolved issue of Bernicia. Carham solved nothing, but it promised this now ambitious dynasty much. Those greater ambitions never materialized, but they were nonetheless a sign of a new confidence amongst mac Alpin kings, born of a novel sense of security on their southern frontier.

The achievement of the mac Alpin dynasty was a considerable but curiously ambiguous one. Malcolm II was hailed by Irish annals as 'King of Alba, the honour of all the west of Europe'. Yet his death marked a genuine crisis in the succession, after kingship passed to his daughter's son, Duncan. The dispute which ensued and threatened the whole mac Alpin line was complex and it is likely some of the key details of the two claimants are unknown. Line Duncan, Macbeth had claim through a female line, via his wife, Gruoch. More significant to each was probably their descent to the male line, by which Macbeth was linked to the Cenčl Loairn. If a dynasty is to be judged by the heirs it leaves, the mac Alpin legacy in the 1030 was an awkward variant of the parable of the talents. That the kingdom survived intact was in effect a twenty-five year war of the mac Alpin succession was a fluke rather than testimony to the strength of the dynasty.