Aelle’s forces had pulled back a half-mile from Aquae Sulis before forming their line and now they waited for Arthur’s attack. Their wizards were capering in the fields between the armies, but I could see no Druids in front of Tewdric’s men. They marched under their Christian God, and at last, after straightening their shield wall, they closed on the enemy. I expected to see a conference between the lines as the leaders of the armies exchanged their ritual insults and while the two shield walls judged each other. I have known shield walls stare at each other for hours while men summoned the courage to charge, but those Christians of Gwent did not check their pace. There was no meeting of opposing leaders and no time for the Saxon wizards to cast their spells, for the Christians simply lowered their spears, hefted their oblong shields that were painted with the cross, and marched straight through the Roman graves and into the enemy’s shields.

We heard the shield clash on the hill. It was a dull grinding sound, like thunder from under the earth, and it was the sound of hundreds of shields and spears striking as two great armies smashed head to head. The men of Gwent were stopped, held by the weight of the Saxons who heaved against them, and I knew men were dying down there. They were being speared, being chopped by axes, being trampled underfoot. Men were spitting and snarling over their shield rims, and the press of men would be so great that a sword could hardly be lifted in the crush.

Then Sagramor’s warriors struck from the northern flank. The Numidian had plainly hoped to outflank Aelle, but the Saxon king had seen the danger and sent some of his reserve troops to form a line that took Sagramor’s charge on their shields and spears. Again the splintering crash of shield striking shield sounded, and then, to us who had the eagle’s view, the battle became strangely still. Two throngs of men were locked together, and those in the rear were shoving the ones in front and the ones in front were struggling to loosen their spears and thrust them forward again, and all the while Cerdic’s men were hurrying along the Fosse Way beneath us. Once those men reached the battle they would easily outflank Sagramor. They could wrap around his flank and take his shield wall in the rear, and that was why Arthur had kept us on the hill.

Cerdic must have guessed we were still there. He could see nothing from the valley, for our men were hidden behind Mynydd Baddon’s low ramparts, but I saw him gallop his horse to a group of men and point them up the slope. It was time, I reckoned, for us to go, and I looked at Cuneglas. He looked at me at the same time and offered me a smile. ‘The Gods be with you, Derfel.’