‘I’m in command here!’ Postumus called out.

Macro let go of the reins and slammed his fist into Postumus’s face. The centurion’s head snapped back and he dropped from the saddle and hit the ground with a jarring crash. Macro shook his head. ‘Not any more you’re not, sunshine.’ He turned to the auxiliaries and shouted, ‘Well? What are you bloody waiting for? Deploy into line!’

Behind him, obedient to his order, the decurions were marshalling the two squadrons into line. As soon as they were ready, Macro raised his sword to get their attention and swept it down towards the caravan.

‘Charge!’

The horses broke into a trot, quickly accelerating into a canter, straight at the oncoming owners of the caravan. They just had time to register a look of surprise and fright before they wheeled their beasts aside, out of the path of the charging Roman cavalry. Then they flashed out of Macro’s field of vision, and he concentrated on the situation ahead as the auxiliaries whooped their war cries and brandished their spears as they closed on the raiders. Already, the first of them was breaking away from the caravan, hurriedly herding a cluster of laden camels ahead of him, back into the desert. As the auxiliaries neared the tail end of the caravan the rest realised the danger and mounted their camels and turned them away. They were in for a nasty shock, Macro thought, when the cavalry didn’t give up the chase and charged right after them. He turned his head to call back to the men behind him. ‘Keep going! Go for them! Don’t stop!’

He wanted them to be quite sure of the order, given that Postumus must have got them used to drawing up as soon as they had chased the raiders away from previous caravans. The auxiliaries pounded round the end of the caravan and headed diagonally across the level ground towards the fleeing raiders. Greed had got the better of the bandits and they did not abandon their loot and the camels they had driven off. Macro smiled. Perhaps they still thought that the Roman cavalry, true to form, was merely making a show of chasing them off. They’d soon discover the folly of that notion.

Macro, at the head of the auxiliaries, was within bowshot of the nearest raiders when they began to understand their peril. One of the camel riders, leading a string of laden beasts, abruptly threw down the lead rope and whipped his camel into a loping run towards the distant dunes. At once his companions did the same, releasing the animals they had seized and desperately racing to escape the horsemen charging towards them. Macro ignored the discarded baggage and waved his sword towards the black-robed figures making for the open desert.

‘Stay on them! Don’t let them get away!’