They crossed the wide brown river, the hoofs of their animals clattering on the boards that linked the pontoons, and rode down the straight streets of Apamea to the desert gate.

Severus was waiting, sitting in the shade of a tomb in the necropolis by the first milestone. The caravan halted to be inspected. The men dismounted. With Decimus, the horse master, Severus went first to the line of short, stocky mules.

‘You still think it was best not to use camels for the baggage?’ Severus asked. ‘Mules can never keep up with horses in a forced march.’

Decimus shook his head. ‘None of the westerners are accustomed to camels. Me included, I have never served in the east before. Well looked after, a mule can go twenty-five miles a day, sometimes thirty.’

Severus gestured to the mare with a bell on her harness at the head of the mules. ‘And that will announce our coming.’

The horse master smiled. No longer young, he was still a strikingly handsome man. A scar by his right eye added to his looks and his only disfigurement was a large wart below the scar. ‘Mules are harder to manage without a bell-mare to follow. If we did not have one, it would look strange, and draw attention.’

As they checked the loads, Valens tightened the girth of his mount. All the animals – the ridden horses and the spares, as well as the mules – had been purchased by Decimus. The chestnut gelding assigned to Valens was small, not much over thirteen hands, and it was not young. Growing up around the stables on his father’s villa, Valens knew horseflesh. He had checked its mouth, but after seven years the age of a horse can no longer be judged by its teeth. Valens was satisfied. A large horse needed more feed, and often lacked stamina, and a young horse could not take as much hard work. The only disadvantage of an older animal was the years made it less resilient to the cold and wet, and he could not imagine that they were going to be a problem in Mesopotamia.

The load on one of the mules had shifted. Severus, holding the beast’s halter, told Narses to remove the pack and the harness. The officer looked around.

‘Valens, help the Persian reload the baggage.’

For a moment Valens stood in disbelief. Was a man of the equestrian order to be treated like some common muleteer?

‘Every man in the column must be able to undertake every necessary task,’ Severus said.

By the time Valens had tethered his horse, Narses had stripped the packages and the rigging.The mule stood quietly. Narses placed the blind over its eyes and took his place on its off side.