The ache in his arms brought Valens back. He drew his bow, fingers back by his ear, tracked a nomad, and shot. The arrow missed. Automatically his fingers found the fletchings of another. This time the arrowhead punched into the haunches of a horse. It screamed as it spun around. Its rider lost his seat, went crashing to the earth.

Without thought Valens sent arrow after arrow into the wheeling mass.

Recovering from the shock, the tent-dwellers were dropping their unwieldy lances, and yanking their own bows from where they hung over their shoulders. Some may be down, but they were still ready to fight. Although the Romans were in cover, and had the advantage in being on foot to aim, they remained outnumbered by at least four to one. They would lose any prolonged exchange. The first surprise had not broken the Arabs. A more drastic gamble was needed to drive them from the field.

Valens felt a near-compelling reluctance to quit the shelter of the rockslide.

Let us be men. It was all or nothing.

‘Horses!’

Letting his bow fall, Valens turned and scrabbled back over the natural barrier. The sharp rocks grazed his hands and arms, tore at his legs.

Decimus was mounted, with difficulty holding the reins of the other four horses. Agitated by the din of battle, the sounds of their own kind in pain, the animals sidled and showed the whites of their eyes.

Valens hurled himself into the saddle. His mount tossed its head, fighting against the bit.

Freed from managing the led horses, Decimus was cutting the ropes of the corral.

‘Close up!’ Valens unhooked his shield from one of the saddle horns, drew his sword.

Zabda came knee to knee one side, Iudex the other.

Clemens went to form the tip of the wedge with Decimus.

‘Hit them as one.’

It had to be now. Any hesitation and the nomads would get over the confusion of the ambush.

They clattered around the end of the landslip at a canter.

Hades, there were a lot of the enemy.

Decimus pushed into a gallop.

There were many tent-dwellers, but they were in no order.

The Romans smashed into their ranks like a stone from a siege engine.

At the heart of the wedge, Valens followed Decimus’s armoured back, Iudex and Zabda on either flank. Then, without warning, the formation was dispersed, and he was alone.

A nomad thrust from his left with a knife. Valens just got the edge of his shield in the way. A splinter of wood stung his cheek. The motion of his mount took him clear.