The Fate of Rome: Climate, Disease, and the End of an Empire, by Kyle Harper, Princeton University Press, 440 pp, £27.95, ISBN: 978-0691166834
One does not have to strain too hard to imagine a few centuries hence Chinese schoolchildren being taught that the US empire fell because hordes of rapists and drug-fiends spilled over its Mexican border, wreaking havoc beyond the capabilities of complacent senators in the Capitol to contain. With their own history of building great walls in failed attempts at keeping barbarians out of the imperial realm the Chinese might be particularly susceptible to such a retelling of American decline. If only they’d listened to that orange emperor, a teacher might chuckle.
The size, splendour and sheer longevity of the Roman empire means its fall continues to haunt some corners of the Western mind at least. This is especially true in the US, such a conscious imitator of Roman political modes. The country seems to have gone from debating whether it possesses an empire straight to worrying about its decline à la romaine. Even anti-imperialists can find Rome’s fate sobering. It was not just an empire that collapsed but a remarkably integrated cultural realm that stretched over three continents from the north of Britain to the Arabian Sea. Its fall marked the end of over a millennium of classical civilisation and those conquered by the legions in the preceding centuries, long since accustomed to thinking of themselves as Romans, lamented its demise.
This epochal event now exists as a warning to those given to worrying about the fate of their own civilisation; it seems to hang over any splendid age like a sombre premonition. One jihadi raid on Paris and Harvard’s Niall Ferguson ‑ a British Greek in Yankee Rome ‑ was out quoting Edward Gibbon’s description of the Visigoth sack of Rome in 410 and warning us that “this is exactly how civilizations fall”.
In making his much ridiculed comparison Ferguson misrepresented the work of fellow British historian Peter Heather whose superb 2005 study The Fall of the Roman Empire: a New History of Rome and the Barbarians is a sophisticated retelling of Rome’s troubled relations with Goths, Vandals and Huns. But Heather is scrupulous in insisting his is a history of western collapse, and argues that the continued survival of the empire in the eastern Mediterranean buttresses his thesis that the barbarians were the primary cause of the western provinces slipping from imperial control.
The Urtext on Rome’s end is of course Gibbon’s The History of the Decline and Fall of the Roman Empire. It is still read for the beauty of its prose, the light it casts on the mind of an Enlightened Englishman in the eighteenth century and to feed the cultural narcissism of anxious imperialists du jour like Ferguson. But despite many piercing insights its analysis of Rome’s end seems increasingly antique.
In Gibbon’s blaming of Christianity as responsible for the “awful revolution” we clearly see the sceptical prejudice of the intellectual elite of his time. His contempt for the impact the otherworldly Nazarene sect had on the classical pagan world led him to frame the period as one of, well, decline and fall. But Gibbon was really more interested in moral decline rather than political collapse as such. After all he barrelled on for almost another millennium after 476, when the last Western emperor was deposed, his contempt for the Byzantines deepening until their Second Rome at Constantinople was conquered by the Ottomans in 1453.
It was through the lens of this declinism that late antiquity was viewed in the two centuries following Gibbon. The historian who has done more than anyone else to lead us away from this paradigm is the Irishman Peter Brown. Over the course of a stellar career he has revolutionised our understanding of the late Roman world and has come to be regarded not just as the doyen but the founder of Late Antiquity studies, one of the most vibrant areas of historical research today.
Brown’s first book, Augustine of Hippo, published in 1967 is hailed by some of its admirers as the outstanding biography of the twentieth century. His second, The World of Late Antiquity: AD 150-750, which emerged just four years later, provided an extraordinarily vivid and empathetic picture of a much-maligned period and in doing so conceptually reframed how we think about the Mediterranean world’s transition from the Greco-Roman to the Medieval.
In luminous prose Brown convincingly argued that what Gibbon had trained us to see as a period of decline and fall was also a time of dynamic intellectual and cultural transmission and transformation, of new beginnings, as the homogeneous, urban, secular culture of the Roman empire morphed into the militarised religiosity of Muslim, barbarian and Byzantine successor civilisations. Rome is indeed sacked in Brown’s telling, but the classical world did not simply vanish, stranded on the wrong side of some radical historical break. Instead it changed into something more recognisable to us, if for no other reason than the period Brown has made his own is when Judaism, Christianity and Islam took on features we can still recognise today.
Brown has been so successful in helping lead us out of the shadow of Gibbon’s Enlightenment intellect that in his wake academics now discuss the “Myth of Decline”. But in fact he never lets his focus on the cultural vibrancy of Late Antiquity obscure from view the concurrent processes of fragmentation, localisation and material and cultural simplification that Mediterranean societies were subjected to as the classical world gave way to something distinctively different. Late Antiquity might have been a time of new beginnings, but it was a supremely painful birth.
By the time of the papacy of Gregory the Great, at the end of the sixth century, the great metropolis of Rome, once home to upwards of a million people, probably had a population of no more than 20,000 and perhaps just half that, small enough to be accommodated in a single corner of the Colosseum. The scale of the collapse meant it was not until around 1800, when London topped one million inhabitants, that a western city would have a population to match Rome’s during the rule of the first Caesars. Why this was so is now better explained in a new book by US historian Kyle Harper. Already the author of two well-received studies of slavery and morality in Late Antiquity, in The Fate of Rome he has written a work that demands serious consideration given that his conclusions have far more troubling implications for our modern civilisation than any inferences we might draw from the barbarian invasions.
Harper sets out to demonstrate how climate change and disease played fundamental roles in the cruel transition from the classical era to the Middle Ages. At first this might sound like once again reshaping our understanding of the past to suit the preoccupations of the present. But this fascinating and at times profound book is too rigorous for such a charge to stick. Right at the start Harper says of the leading exogenous and endogenous theories for the end of Roman supremacy: “These … have much to recommend them, and they remain integral to the story presented in these pages.” He has not come to debunk but instead to set what we know about Late Antiquity on a new and far vaster planetary stage so that we can better understand why events happened as they did.
Take as an example of this approach the question of the Huns. This nomadic people are central to Peter Heather’s thesis that the barbarian invasions were responsible for the collapse of imperial power in the West. Their appearance in Europe overturned the strategic balance along the Danube and Rhine frontiers. The Goths who spilled over the Danube in 376, the group which eventually sacked Rome in 410, did so under pressure from Huns migrating west. These would later go on two rampages of their own through Italy and Gaul under Attila before the collapse of Hunnic power after his death provoked further Gothic migrations into the empire in the political vacuum that followed.
Heather tells us all this in his gripping narrative. But when faced with the long unanswered question of why the Huns migrated from their territory on the Central Asian steppe, he writes: “Unfortunately, we can only guess at the motives behind the Huns’ decision to shift their centre of operations westwards.” This caution makes sense. The Huns left us no written history, nor did the barbarian tribes who fled into the Roman empire before their advance. But armed with a series of Juniper tree rings from Dulan-Wulan on the Tibetan plateau (one of the best high-resolution paleoclimate proxies, apparently) Harper is now ready to hazard an answer.
According to these rings, 350 to 370 AD, the decades immediately preceding the Huns’ appearance in Europe, were years of devastating drought. The Central Asian nomads would have faced a crisis as dramatic as the Dust Bowl storms in the North American prairies in the 1930s, Harper writes, before concluding dramatically: “The Huns were armed climate refugees on horseback.” Caveats follow immediately. The climate did not act alone but in concert with internal Hun social developments. Harper is always at pains to point out that environment interacts with human agency. But his image of ferocious climate refugees wrecking havoc on the Roman world is a striking one.
Harper’s ability to attempt this new sort of history derives in great measure from the current urgency of attempts to understand what we are doing to our planet. The science of climate change has come on in leaps and bounds since the dawning realisation humans are now driving it, leading to a much greater understanding of its history, primarily to help scientists put in context which particular alterations modern civilisation is responsible for. A side effect is to help classical historians to understand much better the environmental context of the Roman period. As a result of the rapid advances in paleoclimate and genomic history historians have come to realise that previous understandings of the environment as a stable backdrop to Rome’s story were “unnervingly wrong”, with Harper instead comparing the earth to “a heaving platform for human affairs, as unstable as a ship’s deck in a violent squall”.
He explains how at first the climate was a strategic ally of the Romans. Their small city state grew to be a superpower in a period now known as the Roman Climate Optimum. This was a phase of warm, wet and stable climate across most of the empire’s heartlands which allowed for an expansion of the agricultural frontier into previously unproductive areas. The resulting bonanza in turn provided the platform for sustained and sustainable population growth that underpinned several of the salient features of an empire that within its frontiers came to contain a quarter of humanity. Foremost among these was the ability to maintain at a relatively light cost an awesome military force of around half a million men without overly straining either the peasants or the widely distributed urban culture we still marvel at today. Protected by the legions and fed by the countryside, the cities in turn spurred further development through trade and technology which exploded under the Pax Romana. It was one of, arguably the, golden age of human development ahead of the early modern period.
And then the empire’s luck turned. In the middle of the second century, the very moment Gibbon famously described as “the period in the history of the world, during which the condition of the human race was most happy and prosperous” the environment ceased to fill the empire’s sails and became instead an increasingly challenging headwind. A period of climate disorganisation marked the three centuries to 450 AD. This was followed by the first stirrings of the Late Antique Little Ice Age, made worse by the level of energy arriving from the sun slipping to its lowest level in several millennia, not to mention a spasm of volcanic activity which in 536 AD resulted in the “year without summer”.
The Roman empire’s very success during the Optimum made it particularly vulnerable to its end. Its population of probably 75 million people was, by the time the climate started to change, a complex but nevertheless still Iron Age society living on the invisible but nevertheless very real razor’s edge that is a primitive agricultural economy. When the Optimum ended food crises appear to have become more common. Feeding the dense patchwork of urban centres became a strain. Environmental challenges worked with geopolitical threats from barbarians and from the Persians to wear down the resilience the Roman world had built up during the centuries of plenty.
Harper most convincingly (and terrifyingly) argues that this classical resilience was most seriously undermined by a series of pandemics that were the cruellest challenges nature posed for the Roman world. The empire’s magnificent achievements made it particularly vulnerable to these invisible enemies. Its military and trading reach was such that it came into direct contact with the microbe-rich tropics. Roman consumer tastes had unforeseen consequences. Once new diseases entered the empire they could spread rapidly because of the empire’s highly developed transport networks. Pathogens found a victim-rich world of densely populated cities that already had an appalling disease ecology given the limited nature of ancient knowledge of hygiene and medicine. In creating such an advanced civilisation Rome had provided a new stage on which previously marginal microbes could cause unprecedented devastation.
The first of these great pandemics was the Antonine Plague of the late 160s and early 170s AD. Probably the first major smallpox outbreak, it struck just as the Optimum was drawing to a close. Harper suggests that the empire’s population never recovered its levels on the eve of the outbreak, with all the demographic implications that implies.
Terrifying new pandemics, inclement climate change, warlike climate refugees. These all combined with once manageable internal contradictions to undermine the empire’s foundations. By 476 the Western provinces were beyond imperial command. But these had always been somewhat marginal to the rest of the empire. Except for Rome the great centres of population and wealth, not to mention intellectual ferment, were in the East and these were all still bound to the emperor in Constantinople. Even in the Goth-ruled West Romanness survived. In Italy Theoderic the Great was nominally a servant of the emperor Zeno. From Ravenna he sought to rule through the old Roman bureaucracy and the Roman senate underwent something of a revival during his reign.
But if one event brought this twilight period of the classical world to a close it was the Justinianic Plague. This first appearance of the Black Death could itself be linked with the brutal cold snap of the 530s and 540s AD when the planet was gripped by volcanic winter, which might have dislodged the host flea from its native Central Asian habitat. When it reached the Roman world it laid waste on an apocalyptic scale; an “unfathomable half of the population” died according to Harper’s best estimate.
And this time the plague came to stay. There were frequent outbreaks for the next two centuries, battering a world already under siege from the Late Antique Little Ice Age, before Y. pestis went quiet until its cataclysmic return in the High Middle Ages. Just before the plague’s appearance a Latin-speaking emperor in Constantinople had reconquered Africa from the Vandals and marched on the old capital, retaking Rome from the Ostrogoths in 536 AD. With his conquests, legal codex and construction of the Hagia Sophia, Justinian wanted to restore the Roman world to order. But the plague knocked the bottom out of his efforts and the long second act of his reign was a grim battle for survival against the elements as much as Rome’s enemies. Endurance involved stripping the machinery of empire down to its essentials. Even then it was not enough. “From the time of the plague, the Roman Empire faced an ultimately irresolvable conundrum. It could not field the army its imperial geography required, and it could not pay for such an army as it was able to muster,” notes Harper. The empire would experience one last, and last-gasp, victory in a titanic final struggle against Persia but its days as a superpower were numbered.
It is under the shadow of plague that the classical world finally becomes medieval. The devastated economies of the Mediterranean world could no longer support the devotion to secular culture that defined classical antiquity. The decimation led to a decisive eschatological turn in both Christianity and Judaism. Harper notes that it is in the sixth century that commentaries on the Book of Revelation, previously a marginal text in the Christian tradition, begin to appear. When the emperor Heraclius went out to defeat the Persians in the last Great War of Antiquity it was as the first Christian crusader, who returned the True Cross to Jerusalem in 629 AD.
It was Rome’s final triumph. The Arabs, with their own new eschatological faith, defeated the Romans at Yarmouk in 636 AD. Without the resources to respond to their challenge Heraclius ordered his armies to draw back. Egypt, Syria and Palestine, the most populous and productive portions of the empire, were lost. What remained was a rump Christian state, the Byzantine empire. It would have its own moments of glory and its inhabitants would consider themselves Romans right until their city fell to the Ottomans. But its history belongs to the Middle Ages.
Harper’s story is a sombre and humbling one. He exhibits huge enthusiasm and patience in explaining the new research. At times the amateur Roman history boffin might think there is a little too much science on topics like the El Niño–Southern Oscillation and “amplification events of variable magnitude arising from interior plague foci”. But there is also a wealth of fascinating information on Roman agriculture, trade, currency, urban sanitation, the Nile floods and Egyptian wheat and grain fleets and the military and much else that is wonderfully woven together to help advance his central thesis, that Rome’s fate was the triumph of nature over human ambitions. Undoubtedly Harper’s conclusions and the work of researchers his book draws on will be tested as the new science of paleoclimate and genomic history advances. And while his argument might be refined some of it too could be debunked, science being what it is. But that depends on future collaborations between scientists and historians.
Until then we are left with his brilliantly marshalled argument and his humane concern for the people whose period he writes about. For all the science this is a deeply compassionate book. The goddess Fortuna had smiled on Rome for centuries, raising the city up to become a power we still marvel at. Then she deserted it. Romans thought the bounty she had provided would last forever, that Roma Aeterna was the natural culmination of human civilisation. They never understood that they had built their world on shifting climatic and epidemiological foundations, to become “a victim both of its own success and the caprice of the environment”. Reading Harper we should be horrified at how climate change, and especially disease, impacted on the Romans but we must also marvel at how its people responded to adversity: we might join him in agreeing with Gibbon that “instead of inquiring why the Roman empire was destroyed, we should rather be surprised that it had subsisted so long”.
As a vastly more advanced civilisation we can look back at the fate of this Iron Age one with a humane curiosity. But after reading Harper we should reflect more profoundly on it. After all we have used the benefits of the Industrial Revolution to swell the planet’s population from less than a billion in 1800 to 7.6 billion today. What if Fortuna were to turn against us? How well would we manage an abrupt change in the climate, man-made or otherwise? Or a dimming of the sun? Are we certain our civilisation is equipped to deal with the threat from “emerging infectious diseases” that lurk in the last corners of the natural environment humans are encircling and penetrating?
Harper concludes thus: “Far from marking the final scene of an irretrievably lost ancient world, the Roman encounter with nature may represent the opening act of a new drama, one that is still unfolding around us. A precociously global world, where the revenge of nature begins to make itself felt, despite persistent illusions of control … This might not feel unfamiliar.”
Perhaps Harper is wrong and our modern civilisation can achieve real rather than illusionary control. Or perhaps Fortuna will never turn her back on us. Such confidence could explain the willingness in the US to raise the climate-change-denying Trump to the purple. Anyone reading this book, however, would agree that it hardly seems sensible to bet heavily on it.
Tom Hennigan is the South America correspondent for The Irish Times and is based in São Paulo, Brazil.