Forward he went.

The Thracians let them come.

I had a ringside seat, on the right of the line. All my Hetaeroi were going to fight mounted, if we had a chance to fight. We were to be the horns of the bull. All my troopers stood beside their horses, well over the crest of the low ridge that separated our main body from the wooded valley – the killing zone.

I had climbed up the low ridge with Philip the Red, and we lay under our dun cloaks in the sunshine – sweating profusely, I suppose, although I don’t remember. I only remember my heart hammering in my chest as our archers began to shoot into the Thracians – Cleitus had taken them right up the valley, and boldly formed a deep ‘v’ where both lines of Psiloi had their backs to the stream.

Our archers outranged the Thracian archers, and were better. The Cretans especially were deadly.

I had never seen a contest of shot before. Our men had training and density of firepower, and the Thracians had the protection of brush and woods.

The protection was not enough. I could see men hit in the woods, and other men moving back up the slopes of the valley, and then there were horns blowing high on the crests of the hills, and sunlight glinted off spears and helmets as the main force of the Thracians moved.

Cleitus did not let his men slacken their shots. Nearer to us, we saw the Rhodian slingers begin to pound away at the exposed Thracians in the low, marshy ground at the nearest end of the valley. Archers can’t stand tight together to loose, and slingers are worse, needing a spear’s length around them; but when a hundred slingers throw all together, their pellets of lead tear at tree branches and pass through brush like a wicked wind. Men screamed.

The archers kept shooting. Philip, at my side, had begun to count arrows, as every archer had twenty-four. The Cretans had loosed sixteen when I saw the glittering might of the Thracian main host start down the ridge.

‘We’re hurting them,’ I said.

Alexander flopped down next to me. ‘Of course we’re hurting them,’ he said. ‘We have more archers and slingers than they’ve ever seen. They have to do something.’

We watched for as long as it takes a slave to start a fire, and then the Thracians began to charge the Psiloi. There was no order, and if anything the trumpet calls were to restrain them. But the wounds – and deaths – were literally driving them down the hill.

They broke cover and took casualties crossing the open ground, because Cleitus – in his first command – held them by sheer force of will for one more volley of missiles. He had so many archers – more than six hundred – they staggered the charge.

Just for a moment, I wondered if the archers could hold the line without us.

Then the Psiloi broke. They all ran together, like a flock of birds taking flight, every wing beating together.

The Thracians were rightbehind them.

Out at the point of the lambda, where Cleitus was, the Thracians caught the Psiloi and killed them.

The rest of the horse came pouring down the hills and into the gap, and our men died.

Alexander lay beside me, counting. ‘See the old chiton tied to the bush?’ he said.

That bush was less than a stade in front of me. ‘Yes,’ I said.

‘When they pass that bush, stand up and wave.’ Alexander got to his feet well to the rear and ran down the slope to where a slave held Bucephalus.

I watched. Our Psiloi were dying in numbers now, running desperately, tangled up with each other. A rout is ugly, and what starts as a trained flight turns all too easily into a rout.

Thracians continued to pour down the slope. I assume – from the hindsight of history – that their king knew he was committed and decided not to send a half-measure. He sent his whole force.

Now they were flowing through the gap, out of the valley and on to the flat ground, up the shallow ridge that closed the southern end of the valley. The first fugitives were passing the chiton. Then more and more.

Behind me, Alexander had opened every tenth file in the phalanx, so that the Psiloi could run through. But the pezhetaeroi were still, for the most part, lying flat, except the men who had to move to open the files.

I don’t think that it mattered any more – the Thracians were committed to all-out attack.

The first Thracians passed the chiton. All the Psiloi who were going to be caught had been caught, by now. The weak. The injured. The unlucky.

I waited a few more breaths, until the main shield line reached the bush, and then I stood up.

I swear that as I stood, the whole Macedonian army rose to their feet. Alexander raised a fist and waved at me, and I raced for Poseidon like a sprinter. A sprinter in greaves and heavy armour.

Polystratus was kind enough to stand at Poseidon’s head and give my butt a push as I climbed on to his broad back. I got up in one go and rode to take my place at the head of my wedge.

Alexander raised his arm. Every man could see him – he was two horse lengths in front, and our whole army took up a little less than six stades.

He pumped his arm. His trumpeter sounded the charge.

And that was the sum total of the commands he gave.

We went up the hill in perfect order. And I don’t use the term ‘perfect’ lightly. Every battle has something I remember – every battle is its own mistress, its own dark partner, its own spectacle. For that battle, it was the moment when we emerged from the brush and started up the hill, and two giants could have drawn a hawser, if one were long enough, taut across the front of the phalanx and touched every man’s chest at the same time.

Just as we crested the low ridge, the flanks began to get a little ahead.

The Thracians were caught flat-footed, spread over two stades of ground, killing the Psiloi they’d caught in no kind of order. A few noble households were all together, shields locked, but most of them were well spread out and unprepared for ten thousand Macedonians to hit them all together.

Just in front of us, the main force of the Psiloi ran past us, eyes wide – registering delight as they crossed the crest and saw the army and the gaps, and men cheered them. Most of the Psiloi had probably never been cheered. Arms reached out in the phalanx and slapped their backs as they ran by, or pressed canteens full of wine on them. We already knew we’d won. And we knew we owed it to them.

I led my squadron of Hetaeroi from the right. The moment I saw the Thracians spread before me like a battle scene on a tapestry, I ordered the charge and we swept forward. Our wedge was unneeded – the wedge is a deep formation for penetrating an infantry block – and instead we passed through the Thracians left like a hot knife through cow’s butter. I doubt that we killed a hundred of them. But Perdiccas and I had the same notion – to get into the entrance to the wooded valley and plug the gap so that the pezhetaeroi could slaughter the Thracians against us, like a hammer against a very small anvil.

We cut our way to the edge of the woods and I wheeled the Hetaeroi right round – try that some time. Great moments in cavalry drill! We got the Hetaeroi around, and formed in shallow blocks – half-files, only four deep. We took up more space that way, and we didn’t need to be eight deep – much less in wedge – to kill Thracians trying to get away.

Then we rode forward slowly, into their rear, killing as we went.

I saw the hypaspitoi slam into a nobleman’s retinue – there was a cloud of dust, as if a giant had thrown a huge clod of earth at the retinue, and then they were gone, and the hypaspitoi went forward overthem. The Thracians went from hunters to hunted in moments, but there was nowhere to go except back into our spears, and we killed so many of them that when the fight was over – and there’s nothing much to tell about that fight – my hand was stuckto my spear shaft, glued with other men’s blood, my hand locked closed from hours of gripping the shaft too hard.