"Very well,' replied Aurelius. 'Anything else?'

'Hold the centre,' said the messenger, repeating his commander's words.

'Hold the centre? That is all?'

The messenger nodded once, wheeled his horse and sped back to join his commander.

Aurelius signalled Gorlas to follow and we started down the hill to the river. At first we did not see what our battlechief intended – perhaps Hengist would not guess either! – but, as we came up behind Uther, the whole front rank, all horsemen, swung out and rode quickly upstream leaving the footmen behind. We moved in to fill the gap Uther left, and to wait.

Hengist greeted this change in the battle array with long blasts on the great Saecsen war horns – those blood-chilling harbingers of doom. The din along the riverbank was deafening.

The Picti danced their defiance, and struck out at easy targets with their evil arrows; Jutes and Frisians banged their spears against their hide-covered shields; Scotti, naked, hair limed and pulled into spiked crowns, their bodies stained with woad, wailed their air-splitting battlesongs; all the while, Saecsen Berserkers howled and slapped each other until their flesh was red and insensitive to pain. Everywhere I looked I saw wild gyrating barbarians, screaming and gnashing their teeth, dashing into the water now and again, taunting, always taunting.

Some few among the High King's warriors had never seen Saecsens before, and were as unprepared for the unholy sight as for the horrendous sound beating in their brains. This display is calculated to unnerve those who must face it, and it accomplishes its aim admirably. If not for the steadying influence of the battle-seasoned in our ranks, I fear many would have broken and run long before the first blow was struck. As it was, we waited, growing impatient and fearful.

It is never good to keep men waiting to go into battle: doubt gnaws holes in even the strongest resolve, and courage leaks away. But there was no help for it – Uther needed time to take up his new position. So, we waited.

Uther's force had disappeared into the brush at the river's edge to the north. This manoeuvre had not gone unnoticed by Hengist, who had moved a portion of his host upriver to meet them. There we stood, face to face with the enemy, neither one of us wanting to cross the stream and thereby give the other an advantage.

It occurred to me to wonder how Uther would cross the water since there was, as far as I knew, only the one fording place along this section of the river. I leaned close to Aurelius, but before I had time to put words to this misgiving there came a cry from the opposite shore. 'Here they come!' cried Aurelius. 'God in Heaven, help us!'

Hengist, having time to assess his position, had decided that Uther's absence more than made up for the disadvantage of fighting with his back to the water, and had signalled the attack – though with the hideous din, how any of them could have heard the signal I will never know.

They came in a swarm: chaos in motion. The sight of the churning mass rolling towards us caused the front rank to draw back involuntarily. 'Steady!' called Aurelius to his chieftains; his command was repeated along the line.

The first enemy reached the shallows to be met by the surge of our own troops. So determined was the foremost rank that the Saecsen should not come ashore, that they halted the enemy rush and forced it back upon itself. The enemy screamed in rage.

From the first blow the battle was hot – so much pent-up fury, nursed through the long summer, kindled it to white heat instantly. Men stood in water to their thighs and hewed at one another with axe and sword. The world was filled with the shattering sound of steel on steel. The Nene swirled around the combatants, its sluggish grey-silted waters blushing crimson.

Only determination kept our smaller force from being overwhelmed outright. That, and the horses, which the barbarians feared – and with good reason, since a good horse is as much a warrior on the field as his rider, and with fearsome weapons of its own.

Nevertheless, little by little, the superior numbers of the foe began to tell. Once the first wind of battle passed and the combatants settled into fighting rhythm, Hengist succeeded in pushing out around our flanks and Aurelius was forced to steal men from the centre to keep the enemy from closing behind and surrounding us entirely.

'Uther must join us soon, or come to bury us,' the High King said grimly, drawing his sword from its sheath. 'We cannot hold the centre much longer without the aid of his horsemen.'

My sword was already in my hand. I lofted it, saying, 'My king, the day is ours! Let us go and wrest it from that heathen prince, and teach him the sting of British wrath.'

Aurelius smiled. 'I believe you mean it, Merlin.'

'Only a fool jests on a field of battle.'

'Then let us begin the lesson,' replied Aurelius, spurring his mount into the fray.

As I say, the centre had been thinned and was in danger of caving in under the barbarian onslaught. So that is where Aurelius struck first, heedless of his own safety.

Uther would have been furious with him, for Uther had taken to protecting his brother, striving to keep Aurelius out of all but the most necessary conflict, saying, 'I have fought too many battles to make him High King for him to get himself killed now.'

You see, Aurelius had no sense of danger. He could not weigh one risk against another; and.this caused him to do things in battle which, counted as courageous in certain situations, became foolhardy in others. Uther knew this about his brother and protected him from it as much as he could.

But Uther was not there and Aurelius saw the need and instinctively went to it, throwing himself into the breach. I have never seen a man so gloriously innocent in battle. It was a joy to watch him fight. And a terror.

A terror, for it fell to me to protect him, and this was no easy task. Aurelius risked enough for two men, and I had my hands full just trying to keep up with him. I did not fear for myself; that never occurred to me. I did fear for Aurelius, however; because, as Uther had suggested, we had endured hardship enough to make Aurelius High King, and I was not about to have him throw it all away in a foolish act – no matter how glorious!

So we fought side by side, my king and I. We were like men joined shoulder to shoulder at birth, matching bladestroke for bladestroke. The enemy fell before us, and our own warriors, seeing their king wading into the thick of the fight, drew courage from the sight and redoubled their efforts. Even so, we could not help giving ground to the barbarian.

With every push, the enemy gained and we lost. We were the shore and they were the storm wave battering against us, dragging us grain by grain and stone by stone into the foaming maelstrom. I felt each successive blast in my bones. And I waited for the shock of the fight to send me into the curiously distorted frenzy that had become familiar to me in battle.

But it did not happen.

It came to me that I had not entered into this heightened state, this battle awen, since Goddeu. I had taken no great part in the battles for Aurelius' kingship. In truth, I had not unsheathed my blade until this day; there had been no need.

I needed it now, however, and now I fought as any other warrior and I found myself wishing for my old sword, against which all other blades shattered as if made of glass – the great sword of Avallach which Charis had given me years ago. What had happened to it?

Had it, like so much else, been lost at Goddeu?

Fool! I had no time to dwell on these things. Keeping myself and Aurelius alive occupied my mind and skill – all the more since the High King would take no thought for himself.

We were now pushed far back from the river – it was either give ground or allow Hengist to surround us – and each blow of the enemy drove us further back. The fight had been carried away from the Nene, although Angle, Jute, Pict, and Irish still swarmed across. Incredibly, the main body of Hengist's host still remained on the other side!