King Magnus went eastward to Viken in autumn with a part of his men and with him Orm, the king's brother; but Earl Erling remained behind in Bergen to meet the Berkebeins in case they took the sea route. King Magnus went to Tunsberg, where he and Orm held their Yule (A.D. 1177).
When King Magnus heard that the Birkebeins were up in Re, the king and Orm proceeded thither with their men. There was much snow, and it was dreadfully cold. When they came to the farm they left the beaten track on the road, and drew up their array outside of the fence, and trod a path through the snow with their men, who were not quite 1500 in number. The Birkebeins were dispersed here and there in other farms, a few men in each house.
When they perceived King Magnus's army they assembled, and drew up in regular order; and as they thought their force was larger than his, which it actually was, they resolved to fight; but when they hurried forward to the road only a few could advance at a time, which broke their array, and the men fell who first advanced upon the beaten way. Then the Birkebeins' banner was cut down; those who were nearest gave way and some took to flight.
King Magnus's men pursued them, and killed one after the other as they came up with them. Thus the Birkebeins could never form themselves in array; and being exposed to the weapons of the enemy singly, many of them fell, and many fled. It happened here, as it often does, that although men be brave and gallant, if they have once been defeated and driven to flight, they will not easily be brought to turn round. Now the main body of the Birkebeins began to fly, and many fell; because Magnus's men killed all they could lay hold of, and not one of them got quarter. The whole body became scattered far and wide.
Eystein in his flight ran into a house, and begged for his life, and that the bonde would conceal him; but the bonde killed him, and then went to King Magnus, whom he found at Rafnnes, where the king was in a room warming himself by the fire along with many people. Some went for the corpse, and bore it into the room, where the king told the people to come and inspect the body. A man was sitting on a bench in the corner, and he was a Birkebein, but nobody had observed him; and when he saw and recognised his chief's body he sprang up suddenly and actively, rushed out upon the floor, and with an axe he had in his hands made a blow at King Magnus's neck between the shoulders.
A man saw the axe swinging, and pulled the king to a side, by which the axe struck lower in the shoulder, and made a large wound. He then raised the axe again, and made a blow at Orm, the King-brother, who was lying on a bench, and the blow was directed at both legs; but Orm seeing the man about to kill him, drew in his feet instantly, threw them over his head, and the blow fell on the bench, in which the axe stuck fast; and then the blows at the Birkebein came so thick that he could scarcely fall to the ground.
It was discovered that he had dragged his entrails after him over the floor; and this man's bravery was highly praised. King Magnus's men followed the fugitives, and killed so many that they were tired of it. Thorfin of Snos, and a very great number of Throndhjem people, fell there.