The bright day darkened and a storm of Persian arrows came slicing down. All around, men were roaring with fury, screaming in pain. Ballista felt an arrow tug at his cloak, saw the sparks as another ricocheted off Pale Horse's armour. He made a signal and turned his tiny column back the way it had come. Everyone feels better with their left, shielded side to the enemy. As if in confirmation of the thought, Ballista was knocked sideways in his saddle as an arrow punched into his shield. Pulling on the horns of his saddle, he hauled himself upright. The bright fletchings of the arrow nodded as he moved, its steel tip embedded in the thick linden boards.
Without conscious thought, Ballista had slipped into the altered state of almost complete calm that sometimes came on him in battle. At the centre of the storm, he looked out over the heads of his infantrymen and tried to work out how the fight was going. Men were falling on both sides. Neither side wore heavy armour. The Sassanids had the advantage of numbers, but the dust and movement made it impossible to judge by how much. On horseback the Sassanids were bigger targets, but then again they were moving.
As the northerner watched, the front rank of Sassanids, no more than thirty paces distant, turned to their right, spun round and headed away. As they retreated they aimed their arrows back over the rumps of their horses, employing the famous 'Parthian shot'. The next rank, and the one after that, and all those following repeated the manoeuvre. Arrows still rained down, but in next to no time the whole force was cantering away.
A great wave of confused noise hit Ballista. It came from up ahead, from near the centre of the Roman line. For a few seconds the northerner could not accept the evidence of his eyes. There was the scarlet and gold figure of Acilius Glabrio out in front of the line. The standard bearers and musicians were with him. Behind him, the column of cavalry surged forward. The heavy cavalry of Equites Primi Catafractarii Parthi were riding through, riding over the line of Roman light infantry. Slingers ran desperately out of the way. One or two, too slow, were bowled over, were either sent spinning like tops or, worse, disappeared beneath the plunging hooves. Acilius Glabrio, scarlet paludamentum flying, was leading his men out in a hell-for-leather charge after the Sassanid light cavalry.
You fool – they are not running, it is just their way. They will turn in a moment. Ballista was not sure if he shouted out loud or not. He found that he had put Pale Horse into a flat-out gallop towards the point where more and more armoured horsemen were pouring out of the Roman formation. Ballista turned in the saddle. His entourage were still with him: Maximus, Calgacus, Demetrius, the others. Good. He called for the trumpeter to sound recall. Towards the rear of the column some of the troopers began to rein in their horses.
Ballista angled his horse into the charging column of catafractarii. His knee crunched painfully into the armoured knee of a trooper. Highly strung for the charge, the trooper rounded on the man who had barged into him then, as he recognized his general, the fight drained out of him. Ballista seized the trooper's reins and pushed their mounts across the four-wide column, bringing those behind them to a skidding halt.
Rising in the saddle, Ballista looked round to take stock. He had managed to prevent about one hundred men of Equites I Parthi leaving the army. But the rest of the unit, some two hundred troopers, were streaming away across the plain.
'Bugger,' said Maximus eloquently. 'Bugger, bugger, bugger.'
Ballista summoned over a decurion. Demetrius quietly provided his name. 'Lappius, I am appointing you in temporary command of those of Equites I Parthi still here with the main body of the army. I want you to get them in order and form them up in close order, knee to knee, in a line two deep, with the right-hand men by the riverbank. Hold that position. On no account move without a direct order from me.' To give him credit, the decurion took this unexpected turn of events in his stride, saluting smartly and barking out orders to make things so.
Staring out across the plain, Ballista watched the rest of Equites I Parthi hurtle towards their fate. They were already some two hundred paces away. The Persians, of course, were giving way before them. But now some of the eastern horse archers were beginning to hang back to lap round their flanks. In a classic manoeuvre, the Persians were drawing the Romans on while flowing around them like water.
Ballista spoke fast but clearly to a messenger. 'Tell Mucapor to bring the Equites Singulares forward. I want them in a line one hundred across and two deep, in open order, a horse's length between each rider, the whole line cantered on me.'
The messenger clattered away. Ballista looked back out over the plain. The majority of the Equites I Parthi still galloped hard after Acilius Glabrio, though now they were strung out like the train of a meteor. Carrying their own heavy armour and their armoured riders, the horses must be nearly blown. Towards the rear, some troopers were slackening their pace. One or two had even stopped and were tuning their mounts.
The jingle of equipment, the stamp of hooves, and the muted grunt of orders announced that his bodyguard, the Equites Singulares, were being deployed behind him, as Ballista wished. He did not turn around, he kept his eyes on the plain. The main group of Roman troopers had come to a halt. He could see the standards still flying above them. They were about four hundred paces away. And the Sassanids were closing around them. Across the plain were isolated Roman troopers. Sassanid light cavalry will fight hand to hand if the odds are well in their favour. One after another, the isolated Roman cavalrymen were dragged down, overwhelmed by sheer numbers as the trap closed. In a matter of moments the main body of Acilius Glabrio's men was surrounded. Arrows were flying at them from all directions.
Leave the bastard there. A small voice spoke in Ballista's mind. The bastard hired someone to kill you. Leave the bastard to die. It is his own fault.
Mucapor approached, saluted, and waited for orders.
But leave the bastard and you leave the rest of them to die…
Ballista returned the salute. 'Mucapor, you will take the right-hand hundred men of the bodyguard, and I will lead the left. We will advance separately, driving the Sassanid horse archers before us until we are on either side and just beyond where, as you can see, the Legate Acilius Glabrio has got his men trapped. Then, while the remnants of Equites I Parthi run back to the army, we will conduct a controlled withdrawal, one line withdrawing through the other so that there are always some troopers facing the enemy.' Ballista paused for questions. There were none. 'The river should help guard your right flank.' As it occurred to him, the general issued orders for Sandario to try to protect the left flank with his slingers.
Ballista indicated where the unit was to be divided. He and Mucapor trotted off in opposite directions to take up their positions in the centre and just in advance of their men. Once in position, Ballista wasted no time making the signal to advance.
They advanced slowly, a walk at first, never rising to more than the gentlest of canters. Ballista gave some of his attention to dressing the line of his men – it was vital they kept together – and some to the Persian horse archers ahead. But much, much more of his mind was directed to piercing the cloud of dust that hung over the plain. Somewhere behind that thick, swirling, red-brown cloud were the Sassanid clibanarii, the terrible heavy cavalry that could sweep over the tiny forces of his own cavalry in a matter of moments.
This is madness, thought Ballista. I am risking the whole army on the off chance of saving a couple of hundred men and a man who probably paid an assassin to kill me.