The news of this slaughter reached William as he was hunting in the forest of Dean; and in a wild outburst of wrath he swore "by the splendour of God" to avenge himself on the North.

But wrath went hand in hand with the coolest statesmanship.

The centre of resistance lay in the Danish fleet, and pushing rapidly to the Humber with a handful of horsemen William bought at a heavy price its inactivity and withdrawal.

Then turning westward with the troops that gathered round him he swept the Welsh border and relieved Shrewsbury while William Fitz-Osbern broke the rising around Exeter.

His success set the King free to fulfil his oath of vengeance on the North.