Behind them the carriage and team were already half round and heading towards the path into the gully. Sling stones struck hard against shields. An arrow hit the old soldier’s shield and punched through the leather and three layers of wood so that the tip was just inches from his body. The arrowhead was long and narrow, tapering to a point, not like the broader heads used by the army’s archers. A second arrow flicked past his face, so close that he could feel the feathers brush him. He glanced back and saw the coach heading down into the gully.

‘Keep together, boys!’ he shouted, not because they needed the instruction but because it was good to hear a confident voice. ‘Not long now. Wait for the word and then we follow.’

A man jerked his shield forward to block an arrow aimed at his horse’s neck and almost spun with the savagery of the blow. Another Batavian was hit on the foot by a stone and spat curses in his own tongue until an arrow took him in the mouth.

The harsh trumpet blew, a deeper call repeated again and again. A horse turned away from the line, shaking its head from a brutal blow. The first arrow took it in the neck, making it fall forward, front legs buckling, and the second slammed into the cavalryman, bit through the rings on his mail shirt and went deep into his belly.

Twenty or more yelling men came streaming out of the woods on the other side of the track, behind the Batavians. They were tall barbarians, wild-haired and carrying the little square shields they liked so much.

‘Go!’ yelled the veteran. ‘Back! Back!’ He yanked on the reins, and the horse, its mouth in pain from the big army-issue bit, turned immediately and bounded back. The last five men were with him, all order gone as they galloped towards the gully. The old soldier saw the coach climbing the far bank; then it seemed to sway. Arrows ripped through the air and he saw the coachman pitch forward as one struck him squarely in the back, the shaft going so deep that little more than the feathers showed. The carriage juddered, then tipped and fell to the left, mules crying out as the weight dragged them back and over.

The screaming was all around them, and the hiss of javelins. Another Batavian went down, a thrown spear knocking him out of the saddle even though it did not pierce his mail. Britons surrounded the fallen man in a moment, hacking down with their long swords. The veteran turned and hurled his spear back, taking one of the warriors in the side as he raised his sword for another slash. Then his horse was at the lip of the gully, and suddenly the beast collapsed under him and he was flung forward through the air, until the ground slammed into him and there was only blackness.

*