This article first appeared in the April 2016 issue of BBC History Magazine


The Roman empire at its height, in the second century AD, stretched from the Sahara to Scotland, from Syria to Spain, and was home to well over 50 million inhabitants.

We might now deplore it: think of the brutal suppression of rebels such as Boudica, the garrisons of occupation in the provinces, or the central imposition of taxes right across the western world. Or we might admire its achievements, from the roads and super-highways that still underlie the transport networks of Europe to the single currency or even the little luxuries of life (such as baths and plumbing) that Rome offered to some lucky residents even as far away as Britain. But, whether we deplore or admire (and for most of us it’s a mixture of the two), we have to ask how on earth an ordinary little town in central Italy actually acquired all that territory.

How did an undistinguished, mosquito-ridden, settlement by the Tiber climb to the top? Starting out back in the eighth century BC, and playing second or third string to much richer and more successful neighbours north and south, what gave it within just a few centuries control over the whole Italian peninsula, and soon over all of the Mediterranean world? It was something no other state has ever managed, before or since.

Thanks in part to Edward Gibbon’s great book, The History of the Decline and Fall of the Roman Empire, we are used to debating why the empire collapsed (Barbarian invasions? Lead in the water pipes? Inflation? Immorality and decadence?). Just as important, and just as puzzling, is why it rose in the first place.

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More than military glory

Some of the favourite explanations just won’t do. For a start, the Romans were not more militaristic than anyone else in the Mediterranean world. To be sure, they put enormous store by military glory. There was no more spectacular ceremony in Rome, at any period in its history, than the triumphal procession, celebrated after all the greatest Roman victories (or bloodiest massacres, depending on your point of view), putting on display, to the cheers and jeers of the Roman crowds, the loot that had been captured and the enemy prisoners taken.

And the earliest examples of Roman boasts to survive, preserved on the first tombstones and sarcophagi of Roman grandees, point to military prowess (“he captured Taurasia, Cisauna and Samnium, he subdued the whole of Lucania and he took hostages”, one epitaph of the early third century BC runs). But in this respect they were no different from any of their neighbours, who were just as committed to warfare as any Romans.

The image we have inherited – partly from the comic strips of Astérix – of a load of thuggish Roman squaddies ploughing into Gaul, where the plucky local inhabitants were busy at their harmless crafts, defended by no more than a magic potion, is quite wrong. In fact one traveller to Gaul in the early first century BC was shocked to discover so many severed enemy heads pinned up outside those pretty little Gallic huts (not something you saw further south – though, he conceded, you did get used to it after a while).

And equally wrong is the idea that the Romans gained control of the Greek world in the third and second centuries BC simply by riding roughshod over a load of philosophers barely capable of putting up a fight. The Greeks who fell victim to the Roman swords were the tough descendants of Alexander the Great, not a bunch of effete intellectuals.

The question is not why the Romans kept going to war. Warfare was endemic in the ancient Mediterranean, peace only rarely broke out, and the Romans were no better or worse than any others. The question is why the Romans kept on winning.

Part of the answer to that might possibly lie in some small element of superior determination in the Roman psyche. But there is no sign that the early Romans had any concerted plan to gain an empire, still less that some cabal of ambitious Roman generals sat down over a map in (say) the fourth century BC, as Roman expansion was beginning to get seriously under way, plotting a world takeover. For a start they didn’t have maps, which made the formulation of any grand territorial plan almost impossible. Even Caesar’s conquest of Gaul seems to have been based on word of mouth not on geographic planning.

An equally small part of the answer might lie in superior military tactics or hardware. The Roman army did have some unusually nasty weapons at their disposal. In a few battle sites in Gaul, for example, the simple Roman equivalent of modern land-mines have been discovered: small hooked iron barbs laid just under the ground surface intended to lodge themselves irremovably and excruciatingly painfully in the soles of the enemy feet. But, by and large, despite many modern myths about Roman military genius, battle tactics in the ancient world were fairly rudimentary on all sides, and superior weaponry was not usually the deciding factor.

What counted most in securing victory was manpower, simply the number of boots you could put on the ground. And that is precisely where the Romans soon found their advantage, by a simple mechanism that was unique in the ancient world: extending its citizenship to outsiders, including those it had defeated and, in the process, massively increasing its fighting force. The secret of Rome’s success was something invisible to the eye, and much more sophisticated than hooked barbs; it was a radically new definition of what “being a citizen” meant, with all the rights and obligations that entailed.

At first sight what the Romans did differently may not seem a huge innovation. The standard pattern of warfare in Rome’s early days (let’s say from the eighth century BC to the fifth, before it had moved very far beyond its own hinterland) was brutal but straightforward. Rome, like its neighbours, would generally have been ‘at war’ in most summers.

‘War’ is perhaps a rather grand term for it. In practice, the sorties would have been not much more than glorified cattle raids between small towns or even villages. If the raiders won, they would have returned home with a good handful of the enemy’s cows and some compensation in the form of bullion (before the age of minted coinage), no doubt leaving a trail of laddish destruction in their wake. It would be a matter of “see you again next year”, when maybe the tables would be turned.

Rules of engagement

The Romans did not change those basic rules of engagement, but they did change their outcome. Instead of just carrying their spoils back home, they gradually came to make permanent links with those they trounced: turning the defeated into Roman citizens, or forming some similar permanent alliance with them.

Why they did this is a mystery, and it may always have been an unplanned, lucky improvisation, rather than a considered strategy. But it had revolutionary consequences. For a start Rome broke the link that applied in most ancient societies between citizenship and birth. The ancient democratic Athenians, for example, had rigorously restricted full Athenian citizenship to those born of two citizen parents. The Romans were emphatically saying that citizenship did not depend solely on where, or to whom, you were born. It was even possible to be a citizen of two places at once: both one’s home town and Rome (the Norman Tebbit ‘cricket test’, as many of us remember from the 1990s, would have asked which team these people would support in a sporting fixture. But the Romans seem to have taken the possibility of dual loyalty on board without as much problem as we’ve had).


In the long term, this set the foundations for the extraordinary multiculturalism of the Roman political hierarchy. It is thanks to these principles laid down early in Roman history that, centuries later, we find on the imperial throne Roman citizens from Spain (including the emperors Trajan and Hadrian) and Africa (Septimius Severus). But back in the early days, those same principles gave the Romans a massive advantage in their battles with their neighbours, and then with enemies further afield – for some obvious reasons.

Citizenship carried privileges, from the right to the protection of Roman law to the right to vote (though how many people from communities miles away would have made the trek to exercise those rights, we can only guess). It also carried obligations, the main one being for the men to serve in Rome’s armies. To put that another way, the more Rome incorporated those they had defeated, rather than leaving them alone to fight another day, the more troops the Romans had to call on.

It was a brilliant mechanism (even if an inadvertent one) for converting one-time enemies into Roman soldiers with a stake in Roman victory – everyone had a share in the rich spoils that came with winning. And it underpinned more Roman victories that in turn produced more Roman soldiers, and more victories, and so on. By the mid-second century BC, according to one canny Greek observer, through this nexus of connections Rome could draw on more than 700,000 troops – more than any western power had been able to do before. When, soon after, Rome’s great enemy, Hannibal from Carthage, knocked out legion after Roman legion, there were always more where they had come from.

Those numbers were the secret of Rome’s success. It would be naive to imagine that no Romans were greedy for the wealth that came from conquest, or that none were relishing the chance of political dominance overseas. And later Romans, looking back, could claim that the Roman empire had been ordained by the gods; Virgil, the great poet of the first century BC, imagined Jupiter, the king of the gods, prophesying that the Romans would have “an empire without limit”. But the root cause of expansion from the fifth century BC onward was the manpower that repeatedly gave it victory, thanks to the unprecedented extension of Roman citizenship.

The Romans themselves realised how important this was, and they underlined that in the stories they told about their own origins. The Athenians, like the citizens of many Greek states, claimed that their original population had miraculously sprung from the very soil of Athens: the land and the people were integrally bound together. The Roman myths were very different, and insisted that the Romans were always in a sense foreigners to their own land.

One Roman story, made famous by Virgil in his Aeneid, told how the Roman race had been established in Italy by a war refugee: Aeneas, in flight from his distant hometown of Troy, after its destruction by the Greeks in the mythical Trojan War. Another focussed on the dilemmas of Romulus who, the story went, had founded the city of Rome on its permanent site on the hills by the Tiber. Romulus realised he had only a handful of citizens, so declared his new town a place of asylum, announcing that criminals, foreigners, runaways and ex-slaves were all welcome. The idea was simple: Rome was built, and thrived, on its incorporation of new citizens.

Indeed it was, and it did. And, in a way, that remains a challenge to our own times. As we see an increasing desire to enforce modern boundaries, we might do well to remember that the biggest empire in the west was proudly built on the idea that it was originally an empire of asylum seekers. I am not suggesting there is a direct lesson; the Romans rarely offer us direct lessons. But it does show us, as we look to close down our own borders, or turn a blind eye to the beaches of modern Greece or camps at Calais, that there is another way of looking at this, and other aspirations to celebrate. The origins of the Roman empire might, indirectly, still have something to teach.


Mary Beard is professor of classics at the University of Cambridge.