There was the same wild panic as the black boats of the invaders struck inland along the river-reaches or moored round the river isles, the same sights of horror, firing of homesteads, slaughter of men, women driven off to slavery or shame, children tossed on pikes or sold in the market-place, as when the English themselves had attacked Britain.

Christian priests were again slain at the altar by worshippers of Woden; letters, arts, religion, government disappeared before these northmen as before the northmen of three centuries before.
[Sidenote: Ecgberht] In 794 a pirate band plundered the monasteries of Wearmouth and Jarrow, and the presence of the freebooters soon told on the political balance of the English realms.

A great revolution was going on in the south, where Mercia was torn by civil wars which followed on Cenwulf's death, while the civil strife of the West-Saxons was hushed by a new king, Ecgberht.
In Offa's days Ecgberht had failed in his claim of the crown of Wessex and had been driven to fly for refuge to the court of the Franks.

He remained there through the memorable year during which Charles the Great restored the Empire of the West, and returned in 802 to be quietly welcomed as King by the West-Saxon people.

A march into the heart of Cornwall and the conquest of this last fragment of the British kingdom in the south-west freed his hands for a strife with Mercia, which broke out in 825 when the Mercian King Beornwulf marched into the heart of Wiltshire.