It’s likely that Oswald took Cadwallon and his men by surprise. The men of Gwynedd had been on campaign for a year or more. It was a long time to be away from home. They had acquired a great deal of booty (the Staffordshire Hoard has vividly illustrated just how much riches could be taken from the body and arms of a dead enemy).

The battle probably started around Corbridge, where the old Roman road crosses the River Tyne. It became a running rout, with Cadwallon and his surviving men making a fighting retreat, down along the course of a river, being forced back and back into the bleak moors until finally the remnants of Cadwallon’s army, and the king himself, were caught beside the Devil’s Water.

There Oswald cut down Cadwallon. The last great hope of a Britonnic reconquest died in the mud.