Lion of the Sun

PART TWO

Ubique Pax (The West, Cisalpine Gaul, south of the city of Mediolanum, Summer AD260)

'O Zeus, what pitiable suffering, what bloody trial approaches that drives you onward, man of sorrows?'

Euripides, Orestes, 332-3

The emperor Gallienus reined in his horse. Its trappings gleamed purple and gold. Well-schooled, it stood quietly, waiting for the ritual to start again.

This time, unexpectedly, a soldier called out from the ranks of the closest unit. 'A coin for a shave, Dominus.'

Gallienus smiled and held his hand out to his a Memoria. Achilleus placed a coin in the emperor's palm. Gallienus flicked it through the air. 'Good luck.'

'May the gods grant you victory, Dominus.'

Another soldier called out. 'Me too, Imperator.'

Gallienus slowly studied the man. 'After due consideration, commilitio, and with the best will in the world, a face like yours is better hidden by a beard.' The soldier himself joined in the laughter as he caught the coin that was thrown in any case.

Gallienus unlaced his helmet and hung it on one of the rear horns of his saddle. He ran his hand through his sweat-dampened, dyed-blond hair. It was hot on the north Italian plain in the summer.

There could never be complete silence in any unit of the Roman army. There was always the clink of metal on metal, the creak of leather, the occasional cough. When it was as quiet as it was going to get, Gallienus raised himself by the front horns of the saddle and began to make his pre-battle speech yet again.

'We have waited a long time and marched a long way for this day. Finally, we have these barbarians where we want them – on an open field, cut off from the mountains and any hope of safety. There are a lot of them.' Not deigning to look, Gallienus languidly gestured over his shoulder to the south. 'It will do them no good. They will merely get in each other's way. They have no disciplina.'

The soldiers banged their spears on their shields.

'These Germans call themselves the Alamanni. They think themselves All Man. We know better. They are all cinaedi. These hairy bum-boys reached Rome. The eternal city is unwalled. They ran from a rabble of plebs and slaves led by a few delicate old senators.'

Gallienus waited for the laughter to subside. 'The quickest and bravest of them have already crossed the Alps. And you all know what happened to them on the other side. The acting governor of Raetia, with just a handful of regular troops and some local peasants, cut them to pieces.'

'We know it. We know it,' chanted the soldiers in their rough northern accents.

Gallienus raised his voice. 'Today we will free Italy from the barbarians. Today we will free our fellow citizens whom they have cruelly enslaved. Today we will take back the Germans' booty and share it among ourselves. By tonight there will not be a poor man in our army!'

As one, the soldiers roared their approval.

'Are you ready for war?'

'Ready!'

As the third repetition of the ritual response was still ringing out, Gallienus looked at Achilleus and his standard bearer. He winked at the two men and nodded forwards. Then, suddenly grabbing his helmet, he kicked his heels into the flanks of his horse. It leapt ahead, closely pursued by those of the other two.

Behind the emperor, his senatorial entourage was caught unawares. They milled in confusion, their horses bumping into each other as they hastened to follow. The soldiers loved it. As he sped away, Gallienus heard them mocking their social superiors before the unit battle cry boomed forth: 'Io Cantab! Io Cantab!'

Gallienus turned into a gap between two of the units and galloped north towards where the reserve of Horse Guards and the rest of his entourage waited.

An emperor never travels alone. As they drew near, the emperor indicated his permission for his a Memoria Achilleus to draw off to one side, where the other heads of his imperial bureaucracy waited. He smiled at their incongruously civilian aspect. There was Quirinius, the a Rationibus, who oversaw his treasury; Palfurius Sura, the ab Epistulis, who handled his correspondence; and Hermianus, his ab Admissionibus. They were all powerful, important men. The imperium could not function without them. But far away from their desks in the imperial chancery, they looked lost.

Holding their horses' heads under the Horse Guards' flag – a red Pegasus on a white banner – the military high command were very different. Three stood out in front: Volusianus, the Italian former trooper, now Praetorian Prefect; Heraclian, once a Danubian peasant, now the commander of the Equites Singulares; and Aureolus, the one-time Getan shepherd promoted to Prefect of Cavalry. Behind them were the other protectores – part bodyguards, part staff officers: three more Danubians – Tacitus, Claudius and Aurelian; two more Italians of plebeian origin – Celer Venerianus and Domitianus; and finally, the Egyptian brothers Theodotus and Camsisoleus, and Memor the African. At the sight of these tough, loyal men, Gallienus's heart lifted.

The emperor dismounted and called for his battle charger. As it was led forward, the senators came up all in a bunch. They radiated hurt dignity. These were the men of Gallienus's father. The emperor Valerian trusted them. He had grown up with several among them; he was one of them. Men like old Felix, who had been consul no less than twenty-three years earlier. He was in his late sixties, but Valerian had trusted him with the defence of Byzantium from the Goths just three years ago. Then there was the yet more elderly and more polyonomous Gaius Julius Aquilius Aspasius Paternus, who had governed Africa in the year of Felix's consulship and had himself held that office at some even more remote date.

For a moment, Gallienus thought he should not have wounded their dignitas to get an easy laugh from the soldiers. To be fair, the Goths had not taken Byzantium, and no harm had come to Africa. But the senators' race was run. In the golden age, when the imperium was conquering all it surveyed – even in the silver age, when it was easily holding its own – its armies could be commanded by elderly landed amateurs, more at home designing an exotic fish-pond than sweating on the march. But this was a new age. A harsh age of iron and rust. It called for a hard, new sort of man. It called for Gallienus's recently formed protectores.

Even in an age of iron and rust, the previous year had been a bad one. Late in the campaigning season, when the leaves in the north had already turned, the Alamanni had burst across the border between the headwaters of the Rhine and the Danube. The governor of Raetia had been cut down in battle, his army routed. The Alamanni had swarmed on and crossed the Alps. Unarmed Italy had been at their mercy. Gallienus had cut short his campaign in the far north near the ocean and desperately given chase, just getting over the mountains before the snow shut the passes. As soon as he and his field army had departed, another confederation of Germans, the Franks, had crossed the Rhine. There had not been enough Roman troops to oppose them, or even to chase them.

Thank Hercules, thought Gallienus, that his second son, the Caesar Saloninus, had been safe with Silvanus the Dux of the Rhine frontier behind the strong walls of Colonia Agrippinensis. Silvanus was a good man. He would see no harm came to the imperial prince. Gallienus pushed away the thought of his eldest son, the beautiful and dead Valerian the Younger. It had been just two years since the boy had died on the Danube. Foul rumours had sought to implicate Ingenuus the governor of Pannonia. But it could not be. Ingenuus was a sound man, loyal through and through to the imperial house. The gods had willed the darling boy die. It just had to be accepted. Take what comfort you could from philosophy, it just had to be accepted.

Gallienus had not caught up with the Alamanni last autumn. They had wintered in Italy, the Franks in Gaul. The barbarians had scoured the land around their quarters. It had been a cruel winter: iron and rust.

As the gods would have it, this year had started better for the Romans. First, in the spring, news had come to Gallienus at Aquileia that yet another northern barbarian invasion had been thwarted. Thousands of Sarmatian horsemen had crossed the Danube into Pannonia but had been resoundingly defeated by Ingenuus. Then had come messengers telling of the repulse from Rome of the Alamanni. In truth, most of the credit was due to Gallienus's brother Licinius. But, for once, some of the senators had played their part. Men such as the Prefect of the City Saecularis and the Father of the Senate Arellius Fuscus. With a wince that almost hurt him physically, Gallienus recalled reading how, in order to keep morale high, his orders to send his youngest son Marinianus to safety in Sicily had been ignored. The infant prince had been paraded in front of the makeshift army. It was fortunate for Licinius that this news had come in a laurel-adorned letter of victory.

Events had continued to unfold well for the Romans. The Iuthungi and the Semnones, two of the tribes that made up the confederation of the Alamanni, had left the main body and set off early for home. As Gallienus had told the troops, the new acting governor of Raetia had massacred them on the far side of the Alps. Simplicinius Genialis had done well in Raetia. Now it remained for Gallienus to finish the rest of the Alamanni here on the plain before the walls of Mediolanum.

'The barbarians are doing something else.' The old senator Felix sounded personally offended.

Gallienus looked at the enemy. The high-priest of each of the three Alamannic tribes on the field – the Hermunduri, Mattiaci and Bucinobantes – had finished the rites to win the favour of Woden and Thor. The magnificent horses and the prisoners who had been selected lay in their blood, decapitated. As each sinistus melded back into the host, he was replaced by a greater number of large figures in wolfskins. Individually, slowly at first, the fur-clad men began to dance. Somewhere among them would be the leader of the expedition, the Alamannic war-leader the Romans called Crocus. Hroc – or Wolfhroc, as his own people knew him, would be dancing and howling, offering his sword to Woden, drawing down the savage, slathering power of the Allfather's beast into his body.

To most Roman eyes, the foreign rites were incomprehensible barbarity; primitive, unchanging, irrational. Apart from those in the ranks with Germanic ancestry, only a few could interpret them. The emperor was one of these few. Gallienus knew he would have understood no more than the majority had it not been for the years in his youth that he was detained at the imperial court as a guarantee of the loyalty of his governor father. There he had been educated with a shy young barbarian hostage from the north. Ballista had opened his eyes to the peoples beyond the frontiers.

Gallienus did not condemn the bloodthirsty rites of the Alamanni. Different gods demanded different things. Only a fool failed to realize that a battlefield was a god-haunted place. How could it be otherwise? Imagine the tedium of immortality. How many years into eternity before one had drunk every wine, sampled every exotic food? Or was one shackled to an unchanging diet of ambrosia, nectar and the smoke of sacrifices? And sex? How many beautiful girls or boys before satiety set in, followed by perverse experimentation then disgust? Think of the boredom of rereading the same books again and again. Imagine the envy of the unattainable emotions of mortals – the sweaty thrill of the unknown, the gripping fear, the true courage in the face of death, the pain of loss. Nowhere were these more sharp than on the field of battle. No wonder the gods came close.

Gallienus could feel his patron god Hercules close by – a crackle in the air, the tightness in his skin, the god-given clarity in his mind. In his battle calm, he surveyed the scene.

The Alamanni were about five hundred paces away. Their infantry was massed in the centre, a solid block of maybe thirty thousand men straddling the Ticinum road. The cavalry, probably in the region of ten thousand horses, were more or less equally divided between each flank.

Gallienus had made his dispositions accordingly. He had about the same number of cavalry. He had stationed four thousand on either wing and kept two thousand back as a reserve. His infantry in the centre were badly outnumbered: just fifteen thousand. But he had arranged a couple of things in their favour. And, above all, he had a plan.

Across the plain, the wolf-dancers had worked themselves into a frenzy. Their howls were being drowned by the start of the massed singing. The various tribes of the Alamanni sang the deeds of their forefathers. The battle would start soon.

Gallienus got into the saddle and turned to his staff. 'Comites, it is time to take your posts.'

The emperor had exercised tact. Old Felix and Volusianus were to command the infantry; young Acilius Glabrio and Theodotus to take the cavalry on the left. There was to be one of the senatorial nobility and one protector at each division but, for the horsemen of the vital right wing, two protectores: Claudius and Aurelian. Gallienus would lead the reserve of Horse Guards himself.

The comites mounted up and saluted. 'We will do what is ordered, and at every command we will be ready.'

Felix spoke up, his aged voice querulous. 'Your plan – it is not Roman. It goes against our traditions and our nature. It is better suited to the guile of barbarians – Moors or Parthians.'

To hide his irritation, Gallienus settled his helmet on his head, laced it tight. 'Then it is good we have four alae of Moors among our cavalry and one of Parthians.' He paused, then spoke heavily. 'The first tradition of the Romans under arms is obedience to orders.'

Wordlessly, Felix saluted again, and turned his horse's head. The commanders of the divisions rode away.

Across the plain, the standards of the Alamanni were raised. As the barbarian advance began, the discordant songs died. They were replaced by the barritus. Low at first, like distant thunder, the German war chant rose from forty thousand throats. The warriors held their shields over their mouths to increase the reverberation. The barritus crescendoed to a harsh climax. It faded away then returned – harder, yet more menacing. Again and again, it rolled across the plain, intermittent, petrifying. Fear enters by the ears.

Gallienus knew the barritus did more than intimidate. The Germans believed it foretold the outcome of battle. If it sounded strong, they thought they would win. It sounded strong.

From the Roman ranks came a medley of war cries. The northern units gave back the barritus. The North Africans, howling and clapping, gave tongue to a faster, higher chant. The easterners wailed an ululating yell.

Gallienus saw that the Alamanni were committed. They came on slowly, the horsemen on the wings keeping pace with the infantry. They were menacingly unified, full of purpose. Fear also enters by the eyes.

There was no need for orders from the emperor. The dice was cast. When the Germans were about four hundred paces away, Volusianus gave the signal for Gallienus's first device to aid his outnumbered infantry. Twang-slide-thump: the quickest of the ballista crews shot. In a moment, the others joined in. Twang-slide-thump. The sound of the torsion artillery echoed along the line of Roman infantry. Almost too fast to see, the bolts sped away.

There were only fifteen ballistae, but their effect was out of proportion to their number. Here and there, holes appeared in the Alamanni ranks. Warriors were punched backwards. Some were pinned grotesquely to the man behind. Shields and mail coats gave no protection against the inhuman power of the steel-tipped bolts.

Stung, seeing their friends and kinsmen die with no way to exact revenge, the Alamanni infantry came on faster. The war-leaders quickened their pace. Their retinues surged behind them. Wedges of the best fighters emerged from the straight line – the boars' snouts that would crash home first.

Out on the flanks, the German cavalry shook their bridles and urged their mounts to stay level with the men on foot.

Like a wind moving a field of corn, a tremor ran through the Roman infantry. Across the left and centre of the line arms swung and threw. Thousands of flashes of light arced out in front and fell to earth. Now battle was irrevocable, Volusianus had ordered the caltrops to be deployed.

A caltrop is a horrible thing: three or four vicious spikes emerging from a ball of metal. No matter how it falls, one, needle-sharp, points upwards. Thousands of them now carpeted most of the ground in front of the Roman infantry, waiting to tear through boots and soft flesh. Gallienus's second ploy was in place.

The emperor looked all around the field. He could feel his god beside him. Once a man like Gallienus himself, Hercules' labours for mankind had won him immortality and Olympus. Now, on this dusty plain before the walls of Mediolanum, Hercules held his hands over the emperor. In his god-given clarity of mind, Gallienus judged distances and speed, estimated time. The Alamanni infantry were within two hundred paces. Disciplined volleys of arrows flew out from the rear ranks of the Roman infantry. Individual Germans shot back on the move. Gallienus's reading of the battle told him it was time; he commanded that the prearranged signal be given.

Trumpets rang out, and his personal standard, a purple draco, hissed back and forth.

A cheer was heard from each flank. From where they were drawn up, a distance behind the infantry, the Roman cavalry walked forward. At the sight, their German counterparts broke into a cacophony of shouts and charged. Quickly, they drew ahead of their infantry. The Roman alae moved to a trot then a canter.

On both wings, the cavalry clashed roughly level with the stationary line of Roman infantry. In a moment, the combatants were intermingled. All order vanished. Squadrons, smaller groups, even individuals charged, wheeled, retreated, then charged again. In both melees hand-to-hand and distance fighting coexisted. Each mounted man sought to press home his attack or seek safety as his courage or circumstance dictated. On the left, Gallienus caught a glimpse of Gaius Acilius Glabrio. The young senator, resplendent in scarlet and gold, was laying about him manfully. Soon, most such details were hidden by plumes of thick dust.

The Alamanni foot were closing. A number of warriors were falling to arrows. A few were still snatched backwards by artillery bolts. The Roman archers and ballistarii were doing their best. They could not stop the charge. A few parts of the German line seemed to hang back, but the wedges headed by the war-leaders and their household warriors were moving fast. Long hair flying, these big, well-armed men were a fearsome sight.

The barritus had dropped to a low murmur. After their long advance, the Alamanni needed their breath. Stationary, the Romans continued to bellow out their war cries.

Gallienus peered through the dust at the cavalry melees. On the left, Acilius Glabrio and Theodotus seemed to be holding their own. At least the swirling dust cloud had not moved appreciably. The right was a different story. The troopers under Aurelian and Claudius appeared unusually reluctant to stay at close quarters. They were giving ground, being driven back behind the Roman infantry line. Gallienus was pleased.

Javelins flew from both sides, just as the infantry of the Alamanni centre and right reached the caltrops. Running close together, pushed on by those behind, some Germans could not avoid the terrible spikes. Others were too distracted by the incoming missiles to notice the menace underfoot until they felt the searing pain. Warriors fell, shrieking. Battle-mad, their comrades ran over them.

The Alamanni crashed into the Roman line. The din hit Gallienus like a blow. There was one huge noise, louder than a temple collapsing, composed of a myriad smaller noises: shield on shield, steel on wood, men shouting, men screaming.

The momentum of the boars' snouts was driving them into the Roman line. Blades and spearheads flashed. Arrows whistled overhead. Men jabbed, hacked, pushed, shouted. Sharp steel bit into flesh. Men fell. The ground ran slippery with blood and spilt intestines. Men lost their footing. They were trampled in the horror by friend and foe alike.

The Roman line looked painfully thin. At the rear, junior officers shouted, threatened, cajoled. They physically pushed men back into line. They beat men with the flats of their swords, yelling for them to give their all.

From somewhere – disciplina? The hand of a god? Hercules himself? – the Romans found the strength to resist. Digging their heels in the ground, bending their knees, calling out to each other, they pushed their shields into the backs of those in front. The line held. The German wedges were halted.

Except for one out on the Roman right, where there had been no caltrops. Tipped by a gigantic warrior, his sword slicing intricate patterns, the one boar's snout edged forward.

Gallienus snapped orders. One unit of his cavalry reserve cantered forward. The men dismounted. Leaving one in five to hold the horses, the armoured troopers added their weight to the threatened point. Four hundred fresh men made the difference. Here too the line held. For the moment.

Blinking from the dust, Gallienus took stock. The cavalry on the left were still holding out but, on the right, the Romans were losing ground fast. A clear gap had opened between this cavalry action and the infantry combat. The feigned retreat had worked. It was time.

There were only fifteen hundred horsemen still in his reserve. Gallienus was not worried. His plan was working. It was time.

Gallienus unsheathed his sword. His palm was wet. His heart was pounding. It was not fear. There was nothing to fear. The god was with him. Like Antony long ago in Alexandria, he would know if Hercules left him. The emperor signalled the advance.

They set off at a walk. With disciplined ease, they changed formation on the move. What emerged would have impressed anyone. Two solid wedges of armoured men on armoured horses. The smaller, some five hundred men, was led by Aureolus, and rode under the red Pegasus on white banner of the Horse Guards. The larger, some thousand men, followed the imperial purple draco. At their apex was the emperor himself.

Without waiting for an order from the emperor, Aureolus angled his horsemen towards the cavalry melee on the right wing. Gallienus approved. The protectores should show initiative, and none more so than the protector appointed Prefect of Cavalry. The emperor watched as Aureolus quickened the pace. The big horses went from a trot to a gentle canter. They moved easily, making little of the weight of man and armour on their backs. A noble cloud of dust rose behind them.

Gallienus led his men towards the gap between the central infantry fight and the mounted one on the right. He kept to a slow walk, fighting down an urge to hurry. He needed to keep his troop together.

A previously unseen ditch appeared in front of Gallienus. Manoeuvring on a battlefield, there was always something. A ditch, a line of vines, a dry-stone wall – an unexpected obstacle always appeared.

The ditch was not too deep, its bottom dry. Gallienus leant back, letting his mount pick its way down, then forward as they climbed out. A few paces across on the far bank, he pulled up, giving the men behind him a chance to sort themselves out.

Gallienus looked to his right. The Pegasus banner streaming above them, Aureolus's troopers were forging into the confused melee. The men under Claudius and Aurelian seemed to have taken heart and were also pressing the enemy. One or two of the Alamanni had had enough. They were spurring their mounts away south across the plain. On that part of the battlefield the tide had turned.

To Gallienus's left, things were not going so well. In the manmade gloom, the thin, thin line of Roman infantry was being forced back. In places it had buckled dangerously. It could not be long before it broke. Now there was no time to lose, no time to fuss over parade-ground cohesion.

Gallienus kicked on, quickly coming to a near flat-out gallop. His men followed. The hooves of a thousand horses rattled on the hard ground as they surged past the cavalry fight on their right. Gallienus led them in a sweeping curve to the left that brought them to about two hundred paces behind the left rear of the German foot.

Now! Strike now! I am with you. The god whispered urgently in Gallienus's heart. No! Not yet. Not like this. Not with the troopers strung out like the trail of a meteor. Hercules had always been hasty. Too hasty when he had sacked sacred Delphi. Too hasty when he had hurled his guest Iphitus to his death from the highest tower in Tiryns. Gallienus, the emperor, who suspected that, one day, he would be a god, stood up to the god who had once been mortal. There was only one throw of the dice. This charge had to break the heart of the enemy, had to rout their infantry beyond recall. Gallienus could feel Hercules' barely suppressed anger, but also his acquiescence. The god still held his hands over the emperor.

Gently, Gallienus brought his mount to a standstill. Horses snorting and stamping, weapons and armour ringing, officers shouting, the troop reined in and got itself back into order.

The warriors in the rear ranks of the Alamanni infantry were more than aware of Gallienus's men. They looked over their shoulders, pointed, gesticulated. Some turned to face the new threat. Others shouted to their war-leaders. If any of the latter heard, caught up in the business of staying alive at the front of the fight, there was nothing they could do.

'Now!' Gallienus spoke as much to his god as to the men behind him. The bucinatores blew the charge. The brassy notes sliced through the din of battle. The now close-ordered arrowhead of armoured horsemen set off. The purple draco writhed and snapped over them as they picked up the pace. The ground seemed to tremble beneath them.

A cavalry charge against infantry was a bluff. It was not so much that, once launched, it was almost impossible to stop, it was more that it surrendered the outcome to the other side. Horses do not run into solid objects. A line of men, shoulder to shoulder, two, three or more deep, was a solid object. One or two horses might be goaded or maddened enough to crash into it, but not several hundred of them. Unless the infantry ran, or at least were scared enough to flinch away, for gaps to open in their formation, the horses would pull up short. The magnificent charge would end up as a chaotic stationary mass; horses wheeling and plunging, riders thrown.

At least, thought Gallienus, as the Horse Guard thundered on, we do not have to cross our own caltrops to get at the nearest enemy. Not to have the right of the Roman infantry line throw caltrops had been a last-moment decision. Memor had pointed it out. The African protector would go far.

The rear ranks of the Alamanni began to swarm like a disturbed wasps' nest. Some warriors who had turned to face the new menace were hefting their shields, standing firm, but others were trying to edge back into the illusory safety of their comrades. A handful had lost their nerve altogether; small groups and lone men were running away to the south-east. Gallienus felt the blood pounding in his head, sensed Hercules beside him. This was going to work.

The emperor aimed at a hole in the line. His charger bowled over an isolated German. The warrior tumbled to the ground, then vanished behind, under the hooves of the Roman cavalry.

A big warrior aimed a cut at Gallienus. The emperor caught the blow on his blade. He rolled his wrist, forcing his opponent's sword wide. He slashed downwards, but missed.

The protectores were trying to catch up and cover their emperor, but Gallienus surged ahead. Sunshine flashing on his blade, he swung left and right. He felt no fear. The god had covered him in his lionskin. The pelt of the Nemean lion was proof against iron, bronze, stone. There was no need for fear.

Three mounted Alamanni appeared out of nowhere, one ahead, one on either side, murder in their eyes. Heraclian, the commander of the Equites Singulares, drove his horse between the emperor and the German to his right. A blow caught him on the helmet. The protector was knocked forward on to his horse's neck. The German drew back his arm for the killing blow. Ignoring the other two enemy, Gallienus leant far out of his saddle, putting all his weight behind the blow. As the impact ran up his arm, Gallienus saw the warrior's helmet buckle. The blood sprayed hot up his arm, into his face.

With god-granted time, Gallienus regained his seat, blocked the slash of the warrior on his left. The German's bearded face twisted in agony as Camsisoleus drove his sword through the mail between his shoulderblades.

The third of the Alamanni had vanished. The immediate threat gone, his protectores around him, Gallienus looked about. Everything had changed. Where there had been battle, now there was rout. Where there had been fighting, now there was only killing. The Alamanni were broken; a mob of individuals fleeing for their lives.

'Horse Guards stay with me,' Gallienus shouted.

The Germans seldom employed a reserve, but Gallienus knew that many a battle had been lost by an overconfident pursuit. The protectores got most of the cavalrymen who followed the emperor back in hand. No one and nothing was going to snatch this victory away from Gallienus.

'Imperator! Imperator!' Fierce faces roared out the traditional acclamation. In the levity of victory, men clasped Gallienus's hand, thumped him on the back. 'Imperator! Imperator!'

Volusianus rode up: 'I give you joy of your victory, Dominus.' Gallienus smiled and shook the veteran's hand.

Aurelian galloped up: 'Claudius is chasing their horsemen on our flank. He will keep our boys in order.' More hugs and handshakes.

Theodotus came to report from the left: 'Acilius Glabrio has hared off after them, but I have a couple of hundred troopers held back.' Yet more rejoicing.

Gallienus felt the exhilaration begin to drain out of him. He heard soft music on the air. The god was leaving. Not for ever, merely withdrawing. Hercules would return to stand with the emperor again. Gallienus looked at his sword. It was slick with blood, right up to the eagle pommel. He sheathed it anyway. Someone else would clean it later. Gallienus noticed his hands were shaking.

Flanked by two of the protectores, a mounted man was led forward. Dressed in travelling clothes stained with sweat, neither very old nor young, the man was familiar to Gallienus, but he could not place him at once. At odds with the surrounding relaxed discipline of success, the man snapped a formal salute. He dismounted and performed proskynesis full length in the dirt. When he got up, Gallienus recognized him.

'Valens, you are a long way from the east.' As he spoke, Gallienus realized something had gone terribly wrong. The governor of Syria Coele should not be here.

'Dominus…' Valens stopped.

Gallienus could feel the tension mounting inside him.

Valens took a deep breath and let the words out. 'Dominus, the Augustus Valerian has been defeated. I am sorry to tell you your father is a prisoner of the Persians.'

A ripple of silence spread outward. In the distance, shouts, screams, snatches of songs, the sounds of victory. Here the silence of shock. In the emptiness, half-formed thoughts raced through Gallienus's mind. Father… too old, too infirm for this. Hercules help me. What should I say? What would an emperor say? What would a Roman of the old republic say? The phrase came fully formed.

'I knew my father was mortal.'

Grim-faced, the officers nodded. The phrase had been good. It had the right gravitas. Gallienus gathered himself.

'How stands the imperium?'

Relieved, Valens spoke a little more normally. 'Carrhae and Nisibis have gone over to the Sassanids. The people of Carrhae opened their gates. At Nisibis, they say a thunderbolt split the walls.' Valens shrugged. 'Whatever, Edessa still held when I left. Shapur had not advanced further.' Valens still looked on edge.

'Who was captured with my father?'

'It is thought some ten thousand men. Many of the high command: Successianus the Praetorian Prefect, Cledonius the ab Admissionibus, Ballista…'

'No!' Aurelian shouted out. Red-faced, he punched his saddle. His horse flinched.

Gallienus remembered the close friendship between Aurelian and the young northerner. 'We will all have lost amici.'

'Dominus,' Valens continued, 'there is more.'

'Speak.'

'When the news reached the Danube, Ingenuus had your portraits and those of your father and son torn from the standards. His men have invested him with the purple.'

A babble of voices rose up in indignation. Gallienus held up his hand for quiet. Valens had not finished.

'On the Euphrates, Macrianus the Lame has taken command of what remains of the field army. He has claimed maius imperium over the east. He has had Exiguus, the governor of Cappadocia, killed. He is appointing his own men to commands. When I fled Syria, it was openly said he would put his sons, Macrianus the Younger and Quietus, on the throne.'

Treachery, revolt, civil war – would it never end? A time of iron and rust. This was not a moment to show weakness. Gallienus knew he had to be decisive.

'When we have killed and enslaved the last of these Alamanni, we will send troops to the Caesar Saloninus on the Rhine. He has good, loyal men around him. Silvanus and Postumus will help him hunt down the Franks in Gaul. We ourselves will march without delay against Ingenuus. When his head is on a pike, we can deal with the cripple in the east.'

Gallienus forced himself to smile. 'The imperium was not won without bitter strife. It will not be held by the faint-hearted. No one has defeated us. We will triumph over these rebels as we have triumphed over these Alamanni.' The emperor raised his voice, made it ring. 'Today we won a heroic victory. Tonight we will hold a heroic feast. We will distribute the booty and then drink until the sun is back in the sky, until the wine peeps through our scars.'

As the protectores and others close enough to hear his words cheered, Gallienus's thoughts flew to the east. Shapur at the head of the Sassanid horde. Macrianus the Lame commanding the Roman forces. And between them, holding the balance, was Odenathus, the Lord of Palmyra. The man they called the Lion of the Sun.