This is my version. Not historically accurate by any means. Here is a snippet of the battle from wikipedia-
The Vikings were at an enormous disadvantage. Their army was divided in two; with some of their troops on the west side of the River Derwent and the bulk of their army on the east side. They were not expecting English intervention, and since it was an unseasonably warm day for late September, they left their armour behind at their ships. The English army arrived and annihilated the Vikings who fought a futile defence on the west side of the river. By the time the bulk of the English army had arrived, the Vikings on the west side were either slain or fleeing across the bridge. The English advance was then delayed by the need to pass through the choke-point presented by the bridge. A later folk story has it that a giant Norse axeman (possibly armed with a Dane Axe) blocked the narrow crossing, and single-handedly held up the entire Saxon army. The Anglo-Saxon Chronicle states that this axeman cut down up to 40 Englishmen. He was only defeated when an English soldier floated under the bridge in a half-barrel and thrust his spear through the laths in the bridge, mortally wounding the axeman.