When the wounded had been tended and the dead buried – or, in the case of the enemy, heaped onto impromptu pyres and set alight – the Saecsen captives were escorted to the coast: back across fields they had destroyed, back through settlements they had decimated on their way to the place of battle. At each place, the survivors came out to rail against them, pelting them with stones and dirt.

Many wanted blood for the blood the Saecsens had spilled: wives for the husbands they had lost; husbands for their dead women and children. But Uther would not be swayed. He did not allow any harm to come to the enemy under his care, though his soul writhed within him. In this, he showed the grace of an angel.

'In truth, Merlin,' he told me when it was finished, 'if I had seen what they had done, I would never have let a single Saecsen escape. I would have made them face the justice of those they had wronged, and there would not be a barbarian drawing breath in all this land tonight, I can tell you.' He paused and dashed down the rest of his wine and then slammed the cup down on the board. 'It is over, and that is something at least.'

Aurelius sympathized. 'Showing mercy to an enemy is battle's most difficult charge. But you have acquitted yourself well, Uther. For your deed this day, you have covered yourself in honour. I drink to you, brother. Hail Uther, Merciful Conqueror!'

It was the night of the day following the battle and Uther was exhausted to the point of collapse. He swayed on his feet – wine and fatigue vying to claim him – his smile thin and uncertain.

'Go to bed, Uther,' I said, holding out a cloak to him. 'Come, I will take you to your tent.'

He allowed himself to be led to his tent where he fell face first onto his pallet. His steward, a west-country youth named Ulfin, was there to help him, but I loosened his boots and belt, and covered him with the cloak. 'Douse the light,' I told Ulfin. 'Your lord will not need it tonight.'

I left Uther asleep in the dark and returned to Aurelius' tent. He was yawning while his steward unbuckled his leather breastplate. 'Well,' he said, 'it looks as if I will be High King after all.'

'You will, my lord Aurelie. There is no avoiding it.' The steward removed the armour and Aurelius scratched himself. 'A last drink, Merlin?' he asked, gesturing towards the pitcher on the board.

'It is late and I am tired. Another night we will drink together. Still, I will pour one for you, if you like.'

'No… ' He shook his head, and the dark curls bobbed. 'Another night it is.' He looked at me pensively. 'Merlin, tell me – did I do right to let them go? Was it the best thing?'

'You did right, my lord. Was it the best thing? No, Aurelius, I fear it was not.'

'Gorlas was right then: they will come back.' 'Oh yes, they will come back. Trust in it,' I replied, adding, 'But they will return in any case and nothing you can do will prevent that.'

'But if I had ordered them put to the sword -' 'Do not let men like Gorlas deceive you, Aurelius, and do not deceive yourself. The barbarians were beaten yesterday, but not defeated. Killing the captives would have changed nothing – save burdening your soul with everlasting shame.'

He dragged a hand through his hair. 'Am I to live with a sword in my hand all my days?'

'Yes,' I told him gently. 'You will rule with the sword as long as you live, my king, for the man has not been born who will hold this land in peace.'

Aurelius considered this, and true to the spirit in him did not shrink from it. 'Well,' he said slowly, 'will I see him?'

I told him the truth. 'No, Aurelius, you will not.' This was harsh to him, so I sought to soften it. 'But he will know you, Aurelius, and he will revere you and win great honour in your name.'

Aurelius smiled, and yawned again. 'That, as Uther says, is something at least.'

I went to my tent through the sleeping camp. How many fewer we were tonight! The men lying on the ground around low-burning campfires might have been dead, so soundly did they sleep. Yes, all the realm slept soundly this night, thanks to these brave warriors and their comrades who now slept under the gravemounds.

In my tent, I fell on my knees to pray, saying, 'My Lord Jesu, Great Giver, Redeemer and Friend, King of Heaven, Beginning and End, hear my lament:

Three times three hundred warriors, bright was their hope, fierce their grip ea-life – three times three hundred we were, but no more, for death has claimed the hero's portion from the blood of good men.

'Three times three hundred, light of life shining full and without wavering, warm was their breath, quick their eyes – three times three hundred but no more, for tonight our sword brothers lie in silent turf-halls, cold and abandoned by their own who cannot follow where they go.

'Three times three hundred, bold in action, keen in battle, steadfast companions when the fire of battle raged – three times three hundred we were, but no more, for the raven croaks over the fields where grief has sown her seeds and watered them with women's tears.

'Merciful Jesu, Great of Might, whose name is Light and Life, be light and life to these your fallen servants. As you delight in forgiveness, forgive them; do not count their sins, rather consider this their virtue: that when the call came to defend their homeland they took no thought for themselves, but roused courage and went forth to do battle, knowing death awaited them.

'Hear me, Lord Jesu, gather our friends to your hall; seat them in your palace in Paradise, and you will not want for finer companions.'

The next day the High King struck camp and rode for Londinium, where his father had been made king, and where his own kingmaking would take place. Pelleas and I rode west to Dyfed, to find Bishop Dafyd. I had it in mind that Dafyd should officiate at Aurelius' accession – if he was as hale as Pelleas indicated, and agreeable to the journey.

Londinium had a bishop, a priest named Urbanus, who, from what I had heard in camp, was a devout if slightly ambitious young man. I had nothing against Urbanus, but Dafyd's attendance would, I thought, further strengthen Aurelius' bond with the kings of the west. Also, I had not seen Dafyd since my return from my long vigil in Celyddon, and this weighed heavily on my heart. Now that I had time to myself once more I desperately wanted to see him.

Pelleas and I rode through a land that seemed to have passed from under the shadow of a preying bird. Everywhere men breathed more freely; we were welcomed in settlements, we met traders on the road, gates and doors were opened – all this, and yet word of the Saecsen defeat could not have travelled from the battlefield. How did the people know?

I believe people living close to the land know these things instinctively; they sense fluctuations in the fortunes of men, as they sense minute changes in the weather. They see a red sunglow at dusk and know it will rain on the morrow; they taste the wind and know that frost will cover the ground when they wake. They apprehend the subtle ripples that great events cause in the atmosphere of the spirit. Thus, they knew without having to be told that some great good had come to them and they did not have to be afraid any more.

They knew, and yet they were glad to have news of the battle from us. This they would repeat to one another for many days until all – toddling child and bent-backed crone alike – could repeat it, word for word, just as it had come from my mouth.

We did not linger on the way, but sped with all haste to Llandaff, which was what men had begun calling the place where Dafyd had built his church: a sturdy rectangular structure of timber on a high stone foundation, surrounded by the smaller huts of the monks. Llandaff was a monastery like the others springing up like mushrooms all over the west country – not a few of them owing directly to Dafyd's tireless work.