Book Review: The Fate of Rome: Climate, Disease, and the End of an Empire


by Kyle Harper

Princeton: Princeton University Press, 2017. Pp. xvi, 420. Illus., chron., maps, tables, diagr., appends., notes, biblio., index. $35.00. ISBN: 0691166838

Why did Rome “Fall”?

Not long ago, in the pages of Natural History magazine, popular science commentator Neil DeGrasse Tryon repeated the old fiction that it was the adoption of Aristotle’s ideas by the early church that stifled the development of science in the West. In fact, for most of the Middle Ages, knowledge of Aristotle was largely confined to the Islamic world. It was only after the translation of Averroes in the thirteenth century that he became known in the West, where his deductive logic was adopted by the Scholastics and eventually provided the basis of the western scientific method. Well – during the last century and a half we have been accustomed to outsiders having a faulty understanding of science – and of scientists knowing little or nothing about anything else, including history, philosophy, art, and literature. Thus it is truly impressive to encounter an author like Kyle Harper who is thoroughly conversant in all these fields, including various branches of science such as medicine, climatology, and archaeology. He effortlessly and clearly synthesizes what they have to say about his topic, the eternal puzzle of the development and collapse of the Roman Empire.

For there is no truly comparable phenomenon except the Chinese Empire, which appeared at the same time, but never – permanently – fell. China had an emperor until 1911, and still exists today as a unified state under a single government, ruling a single people created by that ancient state. History tells us about Rome’s politics and ideas in great detail, and something of what lies beneath the surface: archaeology, economics, sociology, technology, and the natural world during these times, albeit that much of the latter has been little known until the present. But in his Fate of Rome Harper fluently synthesizes knowledge of climate history, infectious disease, ancient literatures, and the Roman economy to give us a thorough “physical” of the Roman Empire, identifying underlying conditions that led to its long health, prosperity, and population growth, but sowed the seeds of its eventual breakdown. The first of these is the “Roman Climatic Optimum”, or “Roman Warm Period” from about 250 B.C. to about A.D. 400, during which higher average temperatures and increased rainfall permitted a very large extension of cultivated land and agricultural productivity throughout the Mediterranean world. The increased food supply led in turn to unprecedented growth in population, social complexity, commerce, and urbanization. Large and numerous cities were connected and supported by trade carried on by a uniquely mobile population using roads, rivers, and sea lanes. Rome was the world’s first city to reach a million people, and required the Egyptian wheat crop for its daily sustenance, brought to it by a government-subsidized system of shipping and distribution.

Yet this huge and interconnected population also fostered the evolution of epidemic disease in unprecedented ways. Disease and mortality constituted a huge part of daily life at this time, largely from malaria and intestinal infections, but the high normal death rate did not impact political events or population size. However three terrible pandemics of a severity then unknown in human civilization swept and devastated, even perhaps halved the Roman population. Previous epidemics were commonplace but limited; these new highly contagious diseases for which people had no immunity, possibly leaping for the first time from some animal reservoir, spread like wildfire throughout the empire, killing vast numbers on a daily basis. Each of these – the Antonine Plague, Plague of Cyprian, and Plague of Justinian – led a highly intelligent and articulate observer to describe its symptoms and effects.

The first of these, the Antonine Plague, struck during reign of Marcus Aurelius, in A.D. 165. Described in detail by the great physician and anatomist Galen, it appears to have been smallpox, and killed perhaps 10-percent of the Empire’s population. It accompanied another new crisis: heavy military pressure from the tribal peoples on the Danube border. Two centuries of peace, prosperity, and good, inexpensive government had created population growth not only within the Empire but outside its northern borders. Tribal peoples were drawn the Roman frontiers by trade and convenience for cross-border raiding, and as their numbers and cultural level grew, so did their political and military organization. Against all his inclinations, the philosopher-emperor Marcus Aurelius was forced to spend all his later years on the front line with his armies dealing with this threat.

But this was just a foretaste of the crises of the third century. A cooling climate led to famine, population drop, and the consequent shortage of funds and manpower needed to maintain the frontiers. A renascent Persian Empire and massive invasions by the Goths on the northern borders led to the collapse of the Roman military situation, economy, monetary currency, and system of imperial succession. Famine, war, and social breakdown were once more accompanied by an appalling pandemic, the “Plague of Cyprian”, named for its chronicler, the saint and Christian bishop of Carthage. Its source seems to have been Ethiopia, and Harper suggests it may have been an hemorrhagic filo-virus akin to Ebola. This torment lasted from 249 to 271, with perhaps 5,000 people dying per day in the city of Rome at its peak. At the time it seemed that civilization, and maybe the world, was ending, but some of the men who grasped the throne – Aurelian, Diocletian, Constantine – offered strong and innovative leadership. The Empire survived, but only with dramatic changes, including a vastly expanded, bureaucratized, militarized, and more expensive government, and with Christianity as its dominant religion.

This new Christian empire solved the problem of monetary hyperinflation and provided military security for another century, until renewed climatic cooling (the “Late Antique Little Ice Age”) and a massive invasion of tribal coalitions driven or led by central Asian steppe nomads, the Huns, conquered the western empire, and temporarily the Balkans in the Fifth Century. This collapse was followed by Justinian’s determination to recover the West in the Sixth Century as part of his very ambitious and expensive program for the overall institutional renewal of the Empire. But once again, disease struck an Empire at a relative peak of prosperity and population – in the East, at least. This time it was clearly identifiable as bubonic plague, described by Justinian’s servant and enemy Procopius, originating in central Asia and affecting China at the same time. This first appearance in history of the “Black Death” took perhaps 50-percent of the Roman population and put paid to all Justinian’s hopes and plans. It has been suggested this plague destroyed the remnants of the Roman military organization that had enabled the Romano-Welsh to hold out against the encroaching Saxons in much of Britain up to this point. It reduced Rome permanently to the eastern “Byzantine Empire” and put it on the defensive for the rest of its existence. This left it vulnerable to invasion from Asia, first by the Sassanid Persians, then – disastrously for both Romans and Persians – by Islam.

To the student of military history, epidemic disease and climate change cannot be left out of consideration when, as in the case of Rome, they affect the underlying factors – resources, population, the institutional ability to cope – which determine a society’s survival in the face of external threats. Perhaps one might think of armies, battles, and tactics as “white blood cells combating localized infections”, but meanwhile the underlying issues of the health and resistance of the organism may be what determines its survival. This book does a remarkable job of synthesizing all the aspects of what might better be called, not the “fall”, but “the long survival of Rome”. Harper’s synthesis is fascinating – great reading. Not only does he span the range of disciplines, but covers very completely the alternative explanations of each specific issue, and he supports his conclusions with full documentation.

A masterful piece of learning, exposition, and intellectual synthesis, The Fate of Rome is an education in itself on a whole range of absorbing questions.


Our Reviewer: Robert P. Largess is the author of USS Albacore; Forerunner of the Future, and articles on the USS Triton, SS United States, the origin of the towed sonar array, and the history of Lighter-than-Air. He has contributed book reviews to ‘The Naval Historical Foundation’ ( and The International Journal of Naval History ( He earlier reviews include The Rules of the Game: Jutland and British Naval Command, King Arthur’s Wars: The Anglo-Saxon Conquest of England, Clouds above the Hill: A Historical Novel of the Russo-Japanese War, and Winning a Future War: War Gaming and Victory in the Pacific War


Note: The Fate of Rome is also available in audio- and e-editions.


StrategyPage reviews are published in cooperation with The New York Military Affairs Symposium


An earlier review of The Fate of Rome appears on StrategyPage for July 27, 2018.

Reviewer: Robert P. Largess   

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