Only in the last five years had he returned to his true self, and that was hard because everyone else remained wary of the madman or worried about the suspected traitor. Crispinus did not think that he was either, not really, and it was hard for an ambitious man to sit idle and watch fools climb the ladder while he stood off to the side. His father had been kind, or at least as kind as the bluff old man could be, as his own health failed him. These days he had to be carried to the table and even the latrine. Three years ago, when his father was still able to walk and talk coherently, he had arranged a marriage. Crispinus’ young bride was of impeccable family, reasonable good looks, negligible intellect and a sweetness of disposition that was childlike. She was swiftly with child – in that respect at least he was as vigorous as ever – and promptly died along with the infant, who was a girl to add to the disappointment. During their marriage Crispinus had indulged but thought little of his wife, which made it all the more puzzling that her death left him so devastated. He felt that he should have done more to be pleasant during her brief life, and he dreamed again and again of her cold, still face lying in death.

‘Are you ready for war?’

‘Yes!’ The cry and the crash of hobnailed caligae slamming onto the ground came together and the sound echoed back off the ramparts.

Crispinus was ready, even if he knew deep down that he feared failure and almost expected it. Nothing had turned out well for him for so very long. A year ago he had fallen in love as hopelessly as a schoolboy, with a hetaira of all things – one of those elegant mistresses from Athens who expected to be wooed and pampered. He had never been in love before and would have despised himself had he not been so happy. She had come with him to the province, then fallen ill after a feast in Antioch. Two days later she was dead. Strange that while he often dreamed of her voice and heard its sweetness in his head, he struggled to picture her face.

The senior optio marched up and stamped to attention beside him. ‘Legio VIIII Hispana requests permission to set out, sir!’

‘Password for today is Hercules Victrix,’ Crispinus said. ‘Noble Caecilius, if you would be so good.’

This was all tradition, and the primus pilus was clearly a man who revelled in tradition.

‘The Ninth Legion will advance!’ Caecilius must have found something to drink because his voice boomed out. There was a clash of metal and wood as the men hefted their shields and brought their pila onto their shoulders. ‘For Rome, for the Senate and People, and for our Lord Trajan. First Cohort, march!’

The eagle and the other standards were at the head of the first cohort, which would lead the column out of the camp. Its remaining centurions repeated the order; the horns and trumpets sounded once more and they all stepped out as one in a rhythmic thumping of equipment. For the moment things were formal, the men marching in silence at attention. Crispinus and the other senior officers sat their horses beside the main gateway and as each file passed, all the heads jerked to face them, the motion like a wave washing back across the formation.