The Pax Romana: how the Romans maintained peace at the point of a sword

In the Dacians, a martial people of eastern Europe whom he had spent all year breaking to the Roman yoke, Trajan had adversaries who, in a similar manner, appeared conjured up from ancient annals. They were strange and menacing and terrible: men who wielded scythes in battle as though they were cutting corn; who bore standards shaped in the form of dragons; who wrote messages on giant mushrooms. All these were the details reported by Hadrian to the senate.

Mood of excitement in Rome

As news of Trajan’s dispatches began to percolate out through the city, the Roman people were swept by a mood of excitement such as they had not known for a long while. “For under the rule of sluggish emperors, they seemed to have grown old and enfeebled; but now, under the rule of Trajan, they were stirring themselves afresh, and – contrary to every expectation – renewing their vigour as though their youth had been restored to them.”

Rome was a city that had been at peace for almost a century and a half by the time that Trajan became emperor. True, back in AD 69, civil war had briefly flared in the capital’s streets. Four Caesars had ruled in succession. Blood had splashed the Forum. The temple of Jupiter on the Capitoline Hill, the holiest in Rome, had gone up in flames. But this sudden eruption of violence had been only a fleeting fever.

The victorious emperor in the civil war, a shrewd and battle-hardened upstart by the name of Vespasian, had briskly restored order to the capital. In the centre of Rome, where the meat market had originally stood, he had commissioned an imposing complex hailed by admiring contemporaries as “a building unrivalled for beauty by any in the world”: a temple to Peace. Vespasian’s aim in commissioning this architectural masterpiece had not been merely to fashion a monument to his own glory – although that had certainly been a motivating factor – but to reassure his fellow citizens that the days of war were truly over.

The temple, adorned as it was with paintings and sculptures sourced from across the world, proclaimed an order that was authentically global. Not just Rome but her entire dominion had been healed of its wounds. The peace to which the temple had been dedicated was very specifically a Roman peace: a pax Romana.

“Empire without limits”

Back in the time of Augustus, the warlord who had presided over the transformation of Rome from a republic to an autocracy, Virgil had described the city’s global rule as an “empire without limits”. The phrase was an exaggeration: even though the Romans had no word for ‘frontier’, everyone knew that there were lands not worth the effort of conquering. What was worth conquering, however, the Romans had conquered. Peace, imposed at the point of a sword, had come to be celebrated even by the vanquished as a gift from the gods.

Three decades on from Vespasian’s accession to power, and the tidings of victory brought by Hadrian from distant Dacia served only to confirm the degree to which the collapse of Rome into civil war during the fateful year of the four emperors had been only a temporary spasm. The Roman legions, whose responsibility it was to keep the dominion won by the Roman people secure against the savages who lurked in barbarous darkness, were patently fulfilling their duty.

Across the vast span of the empire, which stretched from the Atlantic to Arabia, and from the icy northern seas to the Sahara, the entire world seemed radiant with the brilliance of a golden age. The sinews that joined market to market, city to city, province to province held secure. Everywhere the sea lanes teemed with shipping. Never before had the world been so connected. Trajan, whose ambition it was to build a new port beside the mouth of the Tiber, a vast concrete complex where previously there had been only mud and reeds, aimed to make these connections even more secure.

To those who contemplated the Roman empire’s greatness, her sway appeared a wonder and a miracle. “All who had ships at sea grew rich by her wealth.” The capital was not alone in benefiting from the unprecedentedly vast market established by Pax Romana.

The sinews that joined market to market, city to city, province to province held secure. Everywhere the sea lanes teemed with shipping. Never before had the world been so connected

The transport of food stuffs, raw materials and luxury goods, conducted across vast distances on a scale never witnessed before, had enabled cities everywhere in the empire to flourish. Some – Alexandria, Carthage, Antioch – had grown immense on a scale that would have seemed inconceivable to previous generations; but even the most flyblown settlement might boast a library. Famines, when they happened, were notable less for their severity than for happening at all.

Grain, in Trajan’s empire, was just one of the myriad products transported, traded and consumed. The sophisticated framework of laws, the network of agents, the shipping, the harbours, the warehouses, everything that over the course of the previous century had enabled the million and more inhabitants of Rome to be fed, profited millions of others as well. Merchants across the Mediterranean – named by the Romans, proprietorially but accurately, ‘our own’ – treated the great sea as their lake.

Businessmen, cities, entire regions: all could afford to specialise. There seemed no limit to what might be shipped: “gold, silver, jewels and pearls, fine linen, purple, silk and scarlet, all kinds of scented wood, all articles of ivory, all articles of costly wood, bronze, iron and marble, cinnamon, spice, incense, myrrh, frankincense, wine, oil, fine flour and wheat, cattle and sheep, horses and chariots, and slaves.”

This list of the commodities transported to Rome, compiled by a Judaean in the province of Asia, was not intended to flatter. The city, within the limits of her empire as well as beyond them, still had her enemies. Rome, to those who hated her and yearned for her downfall, appeared like a monstrous parasite, swollen with blood and gold.

Baneful luxuries of the Pax Romana

Even Romans, however, even patriots committed to her service, were capable of looking askance at the wealth of the age. The baneful effects of luxury had been a running theme of Roman moralists. One particularly mordant analysis of the Pax Romana, written by a young senator named Tacitus, had begun to circulate in the capital even as Trajan was preparing for his invasion of Dacia. The Agricola, a laudatory biography of Tacitus’s father-in-law, described an estimable record of public service.

Agricola was portrayed in it as a citizen authentically worthy of the noblest traditions of his city: a man who, during his lengthy term as governor of Britain, had proven himself in both war and peace, defeating the savage inhabitants of the island’s northernmost reaches in open battle, while also doing what he could to redeem the natives from their barbarism.

Yet Tacitus, deeply though he admired his father-in-law, could not help but wonder whether Agricola might, in truth, have done the provincials under his stewardship more harm than good. Perhaps, by introducing to the savage Britons all the various refinements of Roman life – baths, fine dining, swanky architecture – he had served to debase them exactly as the Romans themselves had been debased. “For what in their naivety the Britons termed ‘civilisation’ was in reality a mark of their enslavement.”

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The fruits of conquest for the Roman people had been manifold: glory, power, wealth. But what if the fruits of these in turn had been servitude and decadence? The question was one that Tacitus continued to brood upon. In the early years of Trajan’s rule, he had looked to the vast expanses of Germany, where there were none of the luxuries that had so corrupted and softened the Roman people, and dreaded the worst.

For two centuries and more the Germans had preserved their freedom against the full might of the legions. The Caesars, who initially had sought to subdue them, had abandoned the attempt. Limits had been set on the advance of Roman arms. The victories claimed by recent emperors, so Tacitus noted sourly, were “little more than excuses for celebrating triumphs”.

Yet even as Tacitus lamented the softening effects of luxury, the news brought to the capital by Hadrian suggested that Rome’s ancient quality of martial valour might not, after all, be completely dead. Was it possible that at last, under a bold and puissant emperor, she might be ready to resume her career of conquest, and fulfil the destiny ordained for her by the gods? Trajan’s record in Dacia offered even an instinctive pessimist like Tacitus the chance to hope for the best: to dream that Rome might simultaneously rule as mistress of the world and yet be true to her most venerable traditions.

Defeat of the Dacians

Dramatic dispatches continued to be brought to the senate. Trajan was anxious to make the detail come alive. Scene after scene was painted in vivid colours. The emperor crossing the Danube in AD 102 and carrying all before him. Lost standards recaptured. Great rivers bridged. Finally, by the spring of 106, Trajan was ready to close in for the kill. Slowly, painstakingly, remorselessly, he advanced into the depths of Dacia. Every last stronghold he captured; every last bushfire of resistance stamped out.

Then the coup de grâce. The Dacian king, who had fled into the remotest fastnesses of his kingdom, was cornered by a squad of Roman cavalry. Rather than be taken prisoner to grace his conqueror’s triumph, he killed himself. His severed head, delivered to Trajan, was sent onwards to Rome, there – before the gaze of the assembled people in the Forum – to be flung onto the steps that led up the side of the Capitoline Hill. Meanwhile, down in the senate house, Caesar’s dispatches had been delivered to the senators. They were read out, as they had been five years previously, by Hadrian.

Not since Julius Caesar’s conquest of Gaul had there been a feat of arms quite so glorious, so gore-sodden, so lucrative. Hadrian, who had commanded a legion during the final stages of the war, had witnessed for himself the full scale of his cousin’s accomplishment. No one could conceivably accuse Trajan of being soft. Model of discipline and modesty that he was, he had no patience with luxury.

Yet Trajan, on his return to Rome from Dacia, demonstrated himself to be a builder in a long line of builders, a showman in a long line of showmen. When, flush with his Dacian loot, he commissioned a new forum appropriate to the full massive scale of his victory, the complex ended up larger in area than those built by previous emperors combined. Libraries were counterpointed with statues; shopping centres with friezes and arches, and triumphal columns.

Not since Julius Caesar’s conquest of Gaul had there been a feat of arms quite so glorious, so gore-sodden, so lucrative... No one could conceivably accuse Trajan of being soft

So monumental was Trajan’s forum, so overwhelming in its impact, that it set the seal on a programme of building begun more than a century before: the transformation of the city centre from an expanse of brick into one of marble. Augustus had embarked on the programme, and his successors had refined it; but it was Trajan, that stern and rugged captain of the legions, who brought it to its ultimate fruition.

Surrounding his forum there rose a wall as high as it was blank. Beyond it, amid smoke and clamour, the contents of chamber pots continued to be flung from attic windows, and gangs of public slaves to farm excrement from cisterns, and the victims of muggers to lie bleeding in squalid side-alleys, and beggars to sit in huddled clusters beside bridges, and miasmas to rise and creep from the Tiber. But Rome, for all its horrors, was like nowhere in the world, nor like anywhere that had ever been.

“The Romans always win”

Trajan, that best of emperors, had met the challenge set him by the gods: of ensuring that the Roman people had a capital at last that was truly worthy of their greatness. Peace was nothing without an aptitude for war.

That Hadrian, when in due course he succeeded Trajan to the rule of the world, opted for retrenchment rather than continued expansion, and a consolidation of the empire’s frontiers rather than ventures beyond them, did not mean that he ever doubted this. Wintering “amid German snows”, he drilled the legions there as though a great war with the barbarians might be brewing. The excellence of his soldiers’ discipline served to signal to Roman and barbarian alike that the proficiency of the legions was as formidable as it had ever been: lethal, irresistible, terrifying.

The truest show of contempt that Hadrian could display towards Rome’s enemies was not to launch punitive expeditions against them, but to scorn to conquer them. What concern was it to the lord of a spreading garden, after all, that outside its walls, squatting in filth and scratching at their sores, there might lie beggars, envious of the fountains, the fruit trees, the flower beds from which they were barred?

This was why, when soldiers in remote provinces from the capital marked out the limits of Roman rule with timber, or turf, or stone, the existence of such fortifications in no way implied any diminishment in their martial ardour. Quite the opposite. Universal though the Pax Romana reigned under Hadrian and his successors, no one ever doubted what it was founded upon. Peace was the fruit of victory – eternal victory. It was a soldier in the wilds beyond Palestine, scratching on a rock face, who put it best, perhaps. “The Romans always win.”

This article was first published in the August 2023 issue of BBC History Magazine