During the reign of the eastern Roman emperor Justinian, the Mediterranean world was hit by a pandemic whose virulence was exceeded only by the outbreak of the Black Plague in western Europe many centuries later.  The pandemic–commonly known today as the Plague of Justinian–only lasted from A.D. 541 to 542, but there were residual aftershocks of the disease that occurred periodically for two centuries thereafter.  It is important to history not only for its extremely high death toll, but also for the political and economic changes that followed in its wake.

The primary sources for the description of the plague come from Procopius (History of the Wars II.22 et. seq.) and several other chroniclers of minor importance.  Until very recently it was assumed that the plague originated in central Africa and migrated northward; but more recent genetic surveys seem to place its home in China.  Perhaps it was thought to have come from Africa simply because earlier afflictions (e.g., the Athenian plague of the Pelopponesian War in Thucydides’s time) had come from the that continent.  In any case, Egypt is where it first came to the attention of the public.  Procopius describes its course in this way:

From here [Egypt] it spread to the entirety of the world, always moving along and advancing at set intervals.  For it seemed to move as if by prearranged plan:  it would linger for a set time in each place, just enough to make sure that no person could brush it off as a slight matter, and from there it would disperse in different directions as far as the ends of the inhabited world, almost as if it feared that any hidden corner of the earth might escape it.  It overlooked no island or cave or mountain peak where people happened to live, and if it passed through a region upon whose inhabitants it did not lay its hands on or whom it did not affect in some way, it would return to that place at a later time…This disease always spread out from the coasts and worked its way up into the interior.  It arrived at Byzantium in the middle of the spring of its second year, where I happened to be at the time.  [II.22.  Trans. by A. Kaldellis]

The infection would begin by the onset of a mild disorientation and fever; and from here the patient would decline rapidly.  On the day following first contact with the contagion, the stricken patient would experience a swelling of the glands, the groin, armpits, and behind the ears.  At the same time, small black pustules or carbuncles would appear over the body.  These small black scabs were about the size of a lentil, and when lanced would produce a dark bile.  For some people, this would mark the culmination of the disease, and it would soon vanish.  Others were not so lucky.  They would quickly lose all strength and ability to move around; there would be deliriums, profuse sweating, and vomiting of blood.  After five days, they would be dead.

According to Edward Gibbon (Decline and Fall, Ch. XLIII), men were more vulnerable to the disease than women, perhaps because they had greater mobility.  The pandemic moved across all social and economic classes; neither wealth nor marbled walls were adequate defenses against infection.  The emperor himself suffered from it; and although he soon recovered, his experience certainly darkened his already moody disposition thereafter.  Many of those who recovered seem to have lost the use of certain motor skills, even the ability to speak.  Medical science of the day was not, of course, able to cope with the scale of the disaster.  Bodies would stack up in parts of cities because there was no one available to dispose of them.  There was no understanding of how the infection came about, and how it was spread; and it burnt itself out not so much because of anything anyone did about it, but simply because there was almost no one left to infect.

When the disease arrived at Constantinople, the result was calamitous.  Gibbon reports that

[D]uring three months, five and at length ten, thousand persons died each day…that many cities of the East were left vacant; and that in several districts of Italy the harvest and the vintage withered on the ground.  The triple scourge of war, pestilence, and famine, afflicted the subject of Justinian, and his reign is disgraced by a visible decrease of the human species, which has never been repaired in some of the fairest countries of the globe.  [Ch. XLIII].

We cannot say for certain what the death toll was, but it certainly ran into the many millions.  The population of the empire probably decreased by one-fourth.  Such a drastic decline could not fail to have social and political repercussions.  Justinian at the time was engaged in a grand project to reconquer the Western provinces (Italy, North Africa) and fuse them into a new, revivified empire; he had largely succeeded at first, but the decimation wrought by the plague meant that he did not have enough manpower to hold on to his conquests.  Within a generation, the Goths and Lombards had undone all that he had achieved.

Justinian did little to alleviate the sufferings of the people.  He needed money to fund his great building and military projects; for this reason, he refused to lighten the tax burdens of his subjects.  Never greatly popular, these measures made him widely hated.  The plague almost certainly contributed to the empire’s lethargy a century later when it faced the military challenge of a new religion that burst out of the Arabian peninsula:  Islam.

The latest medical research has demonstrated conclusively that the plague was caused by the bacterium Yersinia pestis, the same vector that disseminated the bubonic plague in Europe in later centuries:

[Researchers] confirmed unambiguously that Y. pestis was indeed the causing agent of the first pandemic, in contrast to what has been postulated by other scientists recently. This revolutionary result is supported by the analysis of the genotype of the ancient strain which provide information about the phylogeny and the place of origin of this plague.  As for the second and third pandemic, the original sources of the plague bacillus were in Asia.  “It remains questionable whether at the time of the Byzantine Emperor Justinian only one strain or more were disseminated in Europe, as it was at the time of the Black Death,” suggested Bramanti and Hänsch.

A reflection on this and other pandemics will no doubt generate some reflection, in the philosophical mind, as to whether Man or Nature is a more potent architect of human misery.