There was only one banner, but it was a huge one; a wind-spread expanse of white linen on which was embroidered the red dragon of Dumnonia. The beast, all claws, tail and fire, reared on the flag that caught the wind and almost toppled the horseman who carried it. Even at this distance we could see that the horseman rode stiffly and awkwardly as though he could neither handle his black horse nor hold the great banner steady, but then two spearmen appeared behind him and they pricked his horse with their weapons and the beast sprang away down the hill and its rider was jerked hard backwards by the sudden motion. He swayed forward again as the horse raced down the slope, his black cloak flew up behind and I saw that his armour beneath the cloak was shining white, as white as the linen of his fluttering flag. Behind him, spilling off Mynydd Baddon as we had spilled just after dawn, came a shrieking mass of men with black shields and other men with tusked boars on their shields. Oengus mac Airem and Culhwch had come, though instead of striking down the Corinium road they had first worked their way onto Mynydd Baddon so that their men would link up with ours.

But it was the horseman I watched. He rode so awkwardly and I could see now that he was tied onto the horse. His ankles were linked under the stallion’s black belly with rope, and his body was fixed to the saddle by what had to be strips of timber clamped to the saddle’s tree. He had no helmet so that his long hair flew free in the wind, and beneath the hair the rider’s face was nothing but a grinning skull covered by desiccated yellow skin. It was Gawain, dead Gawain, his lips and gums shrunken back from his teeth, his nostrils two black slits and his eyeballs empty holes. His head lolled from side to side while his body, to which the dragon banner of Britain was strapped, swayed from side to side.

It was death on a black horse called Anbarr, and at the sight of that ghoul coming at their flank, the Saxon confidence shuddered. The Blackshields were shrieking behind Gawain, driving the horse and its dead rider over the hedges and straight at the Saxon flank. The Blackshields did not attack in a line, but came in a howling mass. This was the Irish way of war, a terrifying assault of maddened men who came to the slaughter like lovers.

For a moment the battle trembled. The Saxons had been on the point of victory, but Arthur saw their hesitation and unexpectedly shouted us forward. ‘On!’ he shouted, and ‘Forward!’ Mordred added his command to Arthur’s, ‘Forward!’