Cato's thoughts skated over similar ground to his comrade's, but swiftly moved on to a more strategic level. This particular extension to the Empire might well have been ill-judged. Of course there were short-term benefits for the Emperor in that it had shored up his uncertain popularity back in Rome. But despite Caratacus' capital, Camulodunum, falling into Roman hands, the enemy had shown no great hurry to negotiate, let alone surrender. Indeed, their resolve seemed to have stiffened: under the single-minded leadership of Caratacus every effort was bent towards frustrating the advance of the Eagles. The whole enterprise was proving to be far costlier than the imperial general staff could ever have anticipated. It was clear to Cato that the logical thing to do was to exact a tribute and a promise of alliance from the British tribes and quit the island.

But that would not happen, not while the Emperor's credibility was at stake. The legions, and their auxiliary cohorts would never be permitted to withdraw. At the same time reinforcements would be drip-fed into the campaign – just enough to keep up a marginal momentum over the natives. As ever, politics overrode all other imperatives. Cato sighed.

'Heads up,' Macro hissed, nodding towards the depot gateway.

In the flickering glow of the braziers each side of the track a small body of men marched out into the street. First came four legionaries, then Vespasian, and then another four legionaries. The small party turned in the direction of Verica's enclosure and tramped off into the darkness, watched by the two centurions.

'Wonder what that's all about,' muttered Cato.

'Courtesy call?'

'I doubt the legate will get a warm reception.'

Macro shrugged with an evident lack of concern about the cordiality of Rome's relations with one of the very few tribes prepared to ally themselves to Claudius. He concentrated on a far more pressing issue.

'Another drink? My treat.'

Cato shook his head. 'Better not. I'm tired. Best get back to the hospital, before some bloody orderly decides to reallocate our beds.'

04 The Eagle and the Wolves

Despite the thrill of having survived the desperate skirmish outside the gates of Calleva, Vespasian was in a foul mood as he marched up the stinking thoroughfare towards Verica's enclosure. And not just because he resented the curt summons he had received from the king of the Atrebatans. As soon as he had recovered his breath after entering Calleva Vespasian marched the survivors of the convoy, and the last of his scouts, to the depot. Every spare man had been placed on the walls in case the Durotrigans decided to chance a more ambitious assault on their enemy. At the depot the legate had to deal with a stream of junior officers jostling for his attention. Taking over the small office of the late Centurion Veranius, Vespasian dealt with them one at a time. The hospital was filled with casualties, and the legion's chief surgeon was demanding more men to set up a new ward. The centurion in command of the convoy requested a cohort of the Second Legion be placed at his disposal to guard his wagons on the journey back to the base on the Tamesis.

'I can't be answerable for any supplies until I can get adequate protection, sir,' he said warily.

Vespasian eyed the officer with cold contempt. 'You are answerable for supplies under any circumstances, and you know it.'

'Yes, sir. But those bloody Spanish auxiliaries I was given are useless.'

'Seemed to be doing well enough just now.'

'Yes, sir,' the centurion conceded. 'But it ain't the same as being protected by legionaries. Our heavy infantry put the shits up the natives.'

'Maybe, but I can't spare you any of my men.'

'Sir-'

'None. But I'll send a request to the general for some Batavian cavalry tomorrow. Meanwhile I want a full inventory of the supplies in the depot, and then get as many wagons ready to move as you can.'

The supplies centurion paused a moment, waiting for further explanation, but Vespasian curtly nodded towards the door and beckoned the next man. His priority was getting rations to his men as soon as possible. Already one of his scouts was riding back to the Second Legion with orders to send two cohorts to Calleva. It might be a disproportionate response but Vespasian needed to be sure that he could transfer as much as possible from the depot to the legion. With the enemy raiding in force there was no chance of guaranteeing a steady flow of supplies.

Caratacus had presented him with a neat paradox: if he continued to advance, his supplies would be cut off; yet if he concentrated on safeguarding his supply lines, the advance would be stalled. Further north General Plautius' forces were already stretched perilously thin, and almost none was available for strengthening the convoy escorts, or garrisoning the way stations and this vital depot at Calleva. The miserable show put on by the garrison that afternoon was indicative of the calibre of the men who could be spared for such duties. What Vespasian needed now, more than anything else, was manpower. Fit and well-trained. But, he realised with teeth-clenching bitterness, he might as well wish for the moon.

There was a further problem. The commander of the garrison was dead. Veranius had been an adequate enough officer – adequate enough to be spared for this command – but the Second Legion could ill afford to send another centurion from the campaign being waged against the hillforts. As always, the casualty rate amongst centurions was disproportionately high, given their duty to lead from the front. There were already a number of centuries being commanded by optios, hardly a satisfactory state of affairs…

It was at that point that a messenger had arrived from Verica requesting Vespasian's presence at the earliest convenience.

All of this weighed heavily on his mind as the legate made his way along the dark streets of Calleva, taking care not to slip on the mud and ordure beneath his boots. Here and there orange pools of light spilled across the rutted streets from the open doorways of native huts. Inside, Vespasian could see families clustered about their hearth-fires, but few seemed to be eating.

A tall gateway loomed ahead of the legate and his escort, and two Atrebatan warriors with spears stepped out of the shadows at the sound of approaching footsteps. They lowered the broad leaf-shaped tips of their spears until they could recognise the legate in the gloom. Then they stepped aside and one of the sentries pointed towards the large rectangular building on the far side of the enclosure. As the Romans crossed the open space Vespasian looked round keenly and noted the stables, small thatched storage sheds and a couple of long, low timber-framed buildings within which the loud, raucous voices of men could be heard. This was how Atrebatan royalty lived then – a far cry from the palaces of kings in the distant eastern lands of the Empire. Another standard of civilisation altogether, Vespasian reflected, and one which Rome might just as well not have bothered with. It would take a very long time to raise these Britons up to the level where they could comfortably take their place alongside the more developed of the Empire's subjects.

On either side of the entrance to Verica's great hall, torches wavered gently in the darkness. By their light Vespasian was surprised to see that the building had been completed since his last visit to Calleva. Clearly the king of the Atrebatans had aspirations towards a higher standard of living. Not surprising, Vespasian considered, given that so many of the island's nobles had enjoyed years of exile in the comfortable accommodation afforded by Rome.

A figure stepped out of the imposing entrance hall, a youth in his early twenties, Vespasian guessed. He had light brown hair tied back and was broad-shouldered and tall – taller than Vespasian by a few inches. He wore a short tunic over his check-weave leggings and soft leather boots, a compromise of native and Roman attire.