In 685 Oswiu's son Egfrith crossed the Forth and invaded Pictland with a Northumbrian army, but was routed with great loss, and was slain at Nectan's Mere, in Forfarshire.

Thenceforth, till 761, the Picts were dominant, as against Scots and north English, Angus MacFergus being then their leader (731- 761).
Now the invaders and settlers from Scandinavia, the Northmen on the west coast, ravaged the Christian Scots of the west, and burned Iona: finally, in 844-860, Kenneth MacAlpine of Kintyre, a Scot of Dalriada on the paternal, a Pict on the mother's side, defeated the Picts and obtained their throne.

By Pictish law the crown descended in the maternal line, which probably facilitated the coronation of Kenneth.

To the Scots and "to all Europe" he was a Scot; to the Picts, as son of a royal Pictish mother, he was a Pict.

With him, at all events, Scots and Picts were interfused, and there began the _Scottish_ dynasty, supplanting the Pictish, though it is only in popular tales that the Picts were exterminated.
Owing to pressure from the Northmen sea-rovers in the west, the capital and the seat of the chief bishop, under Kenneth MacAlpine (844-860), were moved eastwards from Iona to Scone, near Perth, and after an interval at Dunkeld, to St Andrews in Fife.
The line of Kenneth MacAlpine, though disturbed by quarrels over the succession, and by Northmen in the west, north, and east, none the less in some way "held a good grip o' the gear" against Vikings, English of Lothian, and Welsh of Strathclyde.