"Black Death" or just the flu?

The "Justinianic plague" also struck the area of modern-day Austria in the 6th century CE; but how bad was the disease?

During this time there was a disease that almost destroyed all of humanity. (...) It is impossible to express an explanation in words unless it is related to God. Because (the plague) not only came about certain people in one part of the world, nor was it restricted to any season (...). It encompassed the entire world and annihilated the lives of all people, even though they differed from one another, and took no account of gender or age. ” Thus, as an eyewitness, the historian Procopius described the outbreak of an epidemic in AD 542 in the Eastern Roman capital of Constantinople ( today's Istanbul), where, according to him, half of the 500,000 inhabitants fell victim to it. Even the then Emperor Justinian I (after whom research names the plague today) fell ill, but recovered again. The epidemic on the Bosporus was introduced via the grain fleet arriving from Egypt. It then spread along the water and land trade routes from the Mediterranean all the way to Ireland. The Roman Empire had collapsed in Western Europe 70 years earlier, but the cross-regional networks were strong enough to allow it to spread. Until the middle of the 8th century, the plague returned in waves.

The Church of Hagia Sophia in Constantinople (now Istanbul), which was inaugurated in 537 a few years before the "Justinianic Plague" broke out (source: https://de.wikipedia.org/wiki/Hagia_Sophia#/media/Datei:Hagia_Sophia_Mars_2013.jpg)


Tracking down the pathogen in the Danube region

The epidemic also hit the Danube region, where in skeletons in the burial ground of Aschheim (north of Munich) the pathogen was first identified by palaeo-geneticists in 2013. It was a strain of the bacterium Yersinia pestis, which was also responsible for the epidemics of the late Middle Ages in Europe (the "Black Death") and the pandemic in East Asia around 1900. If untreated, the mortality rate for sick people was 50-60%; the transmission took place through the bite of infected fleas upon contact with animals (such as rats) or humans affected by fleas. The researchers were also able to determine the genetic relationship of the pathogen of the 6th century with plague bacteria still endemic in rodent populations in eastern Central Asia. A climatic cold period from 536/540 CE onwards gave this region more rainfall, which favored the multiplication of rodents, fleas and bacteria, which increased the risk of the jumping of the disease onto humans. From there, the plague spread to India, from where Roman Egypt imported spices such as pepper, but also semi-precious stones such as garnet, by sea. The latter can be found alongside other “exotic” imports in early medieval burial grounds such as in Aschheim, but also in Upper Austria.

The bacterium Yersinia pestis under the microscope (source: https://commons.wikimedia.org/wiki/Yersinia_pestis?uselang=de#/media/File:Yersinia.jpg)


Globalization and the impact of an epidemic then and now

The early "globalization" thus facilitated the spread of the disease worldwide. But how devastating was its impact? Can we believe the numbers given by Prokop and other historians of the time, or did they spread "fake news"? A debate has flared up due to an article published shortly before Christmas 2019 by Lee Mordechai and his team, who call the "Justinian plague" an "inconsequential pandemic" (see https://www.pnas.org/content/116/ 51/25546). On the basis of a statistical analysis of the frequency of papyri, inscriptions and coins, but also of pollen data (on the intensity of agriculture), they doubt that the plague of the 6th century, like the "Black Death" of the late Middle Ages, caused death for 30 or even 50% of the population – and was thus more like the East Asian pandemic around 1900, which claimed millions of victims, but by no means depopulated large parts of China. Other researchers are strongly opposed to this scenario. Even if the lethality of the epidemic was lower than assumed, the social, economic and psychological consequences of the insecurity of the people and the disruption of normal everyday life should also be taken into account. The latter argument seems understandable given the current situation around the corona virus, considering that the people of the 6th century were completely unclear about the cause and ways of diffusion of the disease.

Map of the possible region of origin and routes of diffusion of the plague epidemic of the 6th century CE (source: J. Preiser-Kapeller, ÖAW, 2020)


Johannes Preiser-Kapeller is a historian at the Division for Byzantine Research of the Institute for Medieval Research at the Austrian Academy of Sciences and conducts research on the global entanglements and environmental history of the medieval world. His lastest book „Jenseits von Rom und Karl dem Großen“ was published in 2018. Website: https://www.dasanderemittelalter.net/.