The centre of the Roman line was held by Macro’s First Cohort, standing four ranks deep. On either side and slightly behind the centre were the two auxiliary infantry cohorts, then further back two more legionary cohorts. Behind the shallow crescent, bulging out towards the enemy, the archers stood in a loose line, ready to fire over the ranks of their comrades when the battle began. A single cohort of legionaries stood in reserve, and the remaining six stood in dense columns at each end of the crescent, as if to protect the army’s flanks from attack. The bolt throwers had been carted forward to form two batteries covering the ground in front of each wing of cavalry.

Once the infantry were in position, Cato gave the order for the recall of the two cavalry cohorts and they formed up on the flanks. In the normal loose hit and run of cavalry skirmishing they would have been heavily disadvantaged by the enemy’s overwhelming number of horsemen and camel riders. However, they were under strict orders not to charge but to hold their ground and protect the flanks of the Roman line.

As the first faint wash of lighter sky appeared over the dark mass of the hills to the east, Cato rode forward to take up his position behind the First Cohort. Macro had already dismounted and sent his horse to the rear. Cato recognised his stocky form standing a short distance to one side of the cohort’s standard. Macro turned at the sound of hoofbeats and raised a hand in greeting.

‘Are your men ready, Centurion?’ Cato called out, loud enough for others to hear.

‘Champing at the bit, sir,’ Macro replied lightly. ‘Keen as anything to get stuck in!’

‘Good! By the end of the day, every standard in the legion is going to have won a decoration!’ Cato reined in and swung his leg over the saddle and dismounted, handing the reins to Junius. He patted Macro on the shoulder and muttered, ‘A word with you.’

When they were beyond earshot, Cato spoke softly. ‘Everything depends on the First Cohort holding its ground today, and the rest the legion timing its move precisely. You understand?’

Macro turned towards him, just able to make out the strained expression on the younger man’s face in the gloom. Cato had briefed him thoroughly on the battle plan the night before, along with the rest of the officers, and once more in person before they had marched out of the camp. Any irritation that Macro might have felt about being reminded of his duty yet again vanished as he recognised the anxiety that was consuming his friend. Macro slowed to a halt and faced his superior. ‘Sir, I know what I have to do. So do the men. Don’t let that concern you. The plan is in place. All that is left now is to wait for the enemy.’

‘And when the Nubians come?’