As Arthur began to elaborate on his plan, all grumbling and vexation ceased. The kings crowded in closer to hear the scheme and their disappointment soon turned to delight.

Although our shadows stretched long on the meadow, we reformed the battlelines according to Arthur's orders and advanced once more into Celyddon – all except the troops under my command. For as soon as the first ranks reached the forest and the fighting began again, those with me broke to horses, mounted, crossed the ford, and began galloping west and south along the Etric glen.

There were a thousand with me under the younger battlechiefs: Idris, Maelgwn, Maglos. We followed the river a goodly way before finding the place Myrddin had described to us – a small dingle where the Etric met a smaller stream, one of countless thousands of burns that flowed out from the forest. This was our entrance.

Abandoning our horses, we took our spears and headed into Celyddon along the burn. We ran reckless through the undergrowth, now in and now out of the water. Our only thought was to reach the battle as quickly as possible. But the burn wandered in the wrong direction! We were moving away from the fray.

'Damn his eyes!' shouted Idris, 'That meddling bard has sent us the wrong way!'

I halted and whirled on him. 'Shut up, Idris! We see it through.'

The others caught us. 'I say we go back,' insisted the stubborn Idris.

Maglos stood undecided, though inclining more towards Idris than Myrddin. But Maelgwn spoke up, 'A blind bard is to be trusted above all else. Who else sees the world so clearly?' He planted the ash haft of his spear between his feet and would not be moved.

I glared at Idris, furious with him for halting our march and provoking the warriors to doubt. I could have run the spear through his arrogant heart. 'I said we will see it through, Idris. Follow me.'

I turned and continued on. Maelgwn followed without hesitation. Maglos and Idris remained stubbornly behind, but when the warriors began passing them, they came along.

The burn continued bending away from the battle site. I trusted the Emrys with my life, but as the sound of the clash diminished, doubt began to creep in. Perhaps Idris is right and Myrddin has misremembered, I thought. Celyddon is so vast; there are so many brooks and burns perhaps this is not the one he thought it was. Or perhaps we have come to another…

No, we must go on. There was no other way. The lives of our kinsmen depended on it. The battle depended on it. If we failed the battle was lost. I clenched my teeth and kept running.

And then, the sound of the battle faded away altogether. I strained after it, and heard only the drum of blood in my ears, and my own rasping breath. Please, God, I prayed, do not let us fail. I kept my eyes on the track ahead and ran, my feet pounding the soft earth even as my heart pounded in my chest. My mouth went dry and my lungs burned, but I swallowed the pain, lowered my head and ran on.

Then all at once we were running uphill and the burn became a straight and open pathway. The trees arched overhead and the water ran swift. Above the sound of rushing water came the faint din of the fight.

The sound grew to a mighty roar. By this I knew we were coming to the battle-place – but now we were behind it. Heaven bless your Most Excellent Bard, he has remembered aright!

There was a pool ahead which the barbarians had used for water, now dark in the failing light. Beyond the pool rose the central bulwark of the earth and timber mazework Baldulf had constructed to thwart us. I could see it through the trees, and I could see the swarming host upon it.

Around the mounded structure, like vast contorted limbs, lay the immense timbered walls of the mazework. It was as Arthur had suggested – the maze had a centre which, because it served to protect the other sections, would not be protected itself. The enemy had trusted the forest to prevent an assault from the unprotected side.

Before me the chaos of battle raged unrestrained. The British warriors struggled against the barriers, gained them, and were time and again turned back. Our Cymbrogi fought bravely. The battle din was a ground-trembling roar, the clash of shield on shield and sword on axe a steadily pounding drum. Fierce was the fight, dread the slaughter.

It was all I could do to keep from dashing in at once and attacking the unsuspecting enemy. But that was not the plan.

Instead, we knelt at the edge of the pool and kindled the brands we had brought with us. This stole precious moments from the fight. Father of Light, kindle your wrath against our enemies and let it burn as brightly as the torches in our hands.

At last, when every man held a flaming brand, up I stood and cried the charge. My shout was answered by a thousand throats and a thousand pairs of feet sprang forward as one.

The startled barbarians turned to see a blazing wall of fire rushing towards them. We fired their camp as we passed through. The flames leapt high and the smoke curled black and thick.

The barbarians quailed to see it. Our sudden appearance inspired alarm, and the blaze of our torches greatly magnified our numbers in their eyes. For in the fading light of the forest they thought themselves surrounded by a numberless fiery foe.

But they quickly gathered courage. Some abandoned their earthwork defence and raced to join battle with us. The charge was ill-timed and inept. It did nothing to halt us, or even divert our path. We drove straight to the timbered mound whereon Baldulf stood to direct the battle.

Upon reaching the foremost earthwork we seized the clay jars at our belts and smashed them against the timbers, spilling oil everywhere. We thrust the torches forth and held them. The oil sizzled and burst into flame. Greasy smoke billowed into the air. Curtains of shimmering flame leapt high. The smoke rolled to heaven. Everywhere along the timbered mazework the assault was repeated and the timbers began to burn.

Now were the barbarian hosts entrapped in a maze of their own making. Battle taunts became shrieks of terror. Men plunged through the flames to the ground and we ran among them with sword and spear, cutting them down.

We had prayed for confusion, and were granted chaos.

Angels and archangels bear witness, we gave the barbarians a taste of the burning hell that awaited them! Oh, it was terrible to see!

The disordered ranks of Angli and Irish collapsed. The Irish screamed and flew to the refuge of the forest. The Angli raged and began slashing at one another in utter hopelessness and frustration. In all, the enemy hordes behaved foolishly, for if they had simply held firm for a moment they would have seen how few we truly were, and how scant the fire.

But it has been said, and indeed proved true, that for all their ferocity and cunning, the barbarians are easily discouraged. They lack the spirit to stay the course. Let their scheme be thwarted and they surrender wildly to despair. They fall away; they die. Myrddin says it is because they do not know how to hope, and I believe him.

We had only to run shouting at them, throwing our torches into their midst, and they faltered. Our simple surprise unnerved them. They yielded not to our swords, but to fear. And it was their doom.

They might have rallied given time, but Arthur snatched that chance clean away. For the instant the barbarians turned to glance behind them at our onslaught, the dauntless Cymbrogi swarmed up and over the embankments. Fire on one side, Arthur on the other – little wonder that so many chose the flames.

With deft, sure strokes we hewed them down. Though they had been a forest, we could not have felled them so swiftly. All around us the enemy wailed. Where one or two brave battlelords stood to fight like men, a dozen others deserted king and kin. Thousands bolted into the dark refuge of the forest.