Alfred waited on his giving-throne, the expression on his long face as calm as it had always been.

In the end, more than a thousand responded to his call.

Alfred climbed up on the seat of his throne so they could all see him and his glittering crown. The farmers before him fell silent, rows of them in their grimy earth-coloured clothes, their faces turned to him like flowers towards the sun.

Alfred spoke loudly enough for the furthest man to hear. He said simply: 'It ends here.'

He was answered by a roar.

The rest of the day was spent in preparations for the battle to come.

The only professional warriors under Alfred's command were his thegns, including Arngrim, and the farmers' only experience of Danes was to run away from them. So the thegns coached the fyrdmen in how to fight the English way, in the shield wall. Arngrim worked hard at this, picking out the younger, stronger and the braver-looking of the farmers and equipping them with shields, mail and decent swords. But there weren't enough weapons to go round.

While Arngrim worked on the farmers' martial skills, Cynewulf tended to their souls. As the day wore on he baptised one scared farmer after another, hastily splashing their heads with water from wooden cups, and sprinkling holy water on their shields. Evidently not all the population of this part of Wessex was as Christian as he might have imagined. But even if they hadn't lived in Christ these farmer-warriors would fight and die as Christians.

At the end of the day Alfred's priests led a long evening of fasting, praying and the singing of hymns and psalms. The camp became an open-air cathedral of Christian piety. Alfred himself was at the centre of this, as tireless in his worship as he had been in preparation for the battle. He was the first to dedicate his life and his victory to God, swearing oaths on a Bible and on the holy sacrament, and he sang until his voice was scratchy with fatigue.

But these final services were conducted under high gibbets on which dangled the corpses of Danes, captured, drained of their useful information, and then summarily hanged. Alfred was pious, but he was a warrior-king.

Not all Alfred's thegns were Christian. Arngrim was nowhere to be seen during these services. With others, he crept off to a bonfire away from the Christian celebrations.

At about midnight, with a couple of his hearth-companions at his side, Alfred left his camp and made for the pagans' bonfire. Cynewulf was worn out with praying, and yet he was too excited to sleep, and he followed the King.

By the light of their bonfire the pagan thegns with their followers stood around a pit. Arngrim was here, and Cynewulf saw Ibn Zuhr tending Arngrim's horse, nearly invisible in the dark. As Cynewulf watched, a pig was dragged squealing to the edge of the pit. A brisk sword-stroke slit open the pig's belly. As grey ropy guts tumbled out of the screaming animal, the thegns took turns to stab it; Arngrim stepped up in his turn and thrust Ironsides into the bloody mess. Then the pig was hurled into the pit. The warriors raised their dripping swords over the hole in the earth and bellowed an oath in a tongue that had come across on Cerdic's boats: 'To Woden! To victory! To death!'

As the warriors prepared to drag forward another animal, a goat this time, the King walked forward. The thegns turned to him respectfully.

'A waste of good pork, that.'

Arngrim smiled. 'We who fall will enjoy it in the Upperworld with Woden.'

Alfred took his shoulder. 'If you were Christian you would be my hearth-companion. You know that.'

'That and if I could read.'

'Well, that too. Do you understand that I will build my kingdom on Christ and on literacy? For Christianity is the root of the morality that underpins the law, and if a law is written down all men may understand it and see that it is fair.'

Cynewulf was struck by the vision of this man who dreamed of law codes even as he prepared for the battle of his life.

Arngrim said, 'But it's not for me, my lord. I'm no monk.'

'No. But tomorrow is for you, Arngrim. I dream of a civilised time when we no longer name our swords. But tomorrow I need warriors.

'I have pondered what was said to me that night, when the damaged girl-child recited her prophetic calendar for me. The prophecy made me aware of our place in history – for these are days that men will talk of for ever, Arngrim, whatever becomes of us. What are we, we English? Four centuries ago we were as these Northmen are now. We gazed with incomprehension on the Romans' mighty ruins. Now these Northmen erupt in our lives, illiterate pagan savages, who are as we were. The priests say that pagans remember hell. Well, the Northmen are our own deep lost memory of hell. And to fight them we will have to reach back for our own true selves, our hell-souls.' He squeezed Arngrim's shoulder tighter. 'And so I reach to you. I need you in the shield wall, Arngrim, at its very centre.'

'You will have me there, lord.'

'But, Arngrim, remember this-you must think. For it is by thinking that we will prevail.' Alfred held his gaze a moment longer, then released him, and moved on to the next man.

The pagan ceremony went on. The goat was dragged forward, butchered in its turn, and its blood stained a dozen swords before its carcass was thrown after the pig's into the pit.

Arngrim, his brow streaked with blood, grinned at Cynewulf. 'A bit more exciting than your chanting monks, isn't it, priest?'

'Goading me is unworthy at such a time, cousin.'

'Well, perhaps. We all have our own ways of preparing to die.' Arngrim held up his sword and kissed its bloody blade. 'I have sworn to Woden that if he spares my life tomorrow I will give him Ironsides – I will break his blade and hurl him into the river myself. And tonight I must make a greater sacrifice.' He gestured at the pit. 'A goose, a dog, a sheep and a goat, a pig, a boar, a bull, a stallion – and a man. That's what is required of us tonight, to feed the pit. And so it falls on me to supply the horse.'

He turned. Ibn Zuhr, standing nearby, stroked the neck of Strong-and-Fleet. The horse pawed the ground and shook his head, disturbed by the stink of blood and fire.

Cynewulf gasped. 'You can't be serious. You love that horse.'

'Better than most of my family. But he has already done his job, in carrying me here; I will have no need of him tomorrow. Or,' he said thoughtfully, 'I could discharge my obligation to Woden by giving him a man.' And he flashed his sword at Ibn Zuhr, pressing the tip of its blade under the Moor's chin. 'We kept a Dane alive for the purpose, but a Moor will do just as well. That way I get to keep my horse, and rid myself of a mouth that flaps before kings. What do you think, cousin?'

Cynewulf dared say nothing. With astonishing calm Ibn Zuhr continued to stroke the restless horse. Arngrim turned away with a laugh, lowered the sword, and the moment was broken.

Arngrim took the horse's reins from Ibn Zuhr, ignoring the Moor. He patted Strong-and-Fleet on the muzzle, and the fine old horse ducked his head. 'Come on, Fleet. You've one last service to perform for me…' He led the horse towards the pit. Cynewulf saw a Dane being dragged forward by two burly English, cowed and beaten.

Through all this Ibn Zuhr had said not a word. But, Cynewulf saw, his eyes burned.