An international team of researchers has confirmed the existence of the first Mediterranean mass grave linked to the Plague of Justinian, the oldest documented pandemic in the region, which ravaged the Byzantine Empire between 541 and 750 AD. This discovery, located in the ancient city of Jerash, in Jordan, allows us to understand not only the presence of the pathogen, Yersinia pestisbut also the experience of urban populations faced with this health disaster. The results were published in the February edition of Journal of Archaeological Science and provide a rare window into urban life, mobility and vulnerability in late antiquity.
Jerash, today famous for its well-preserved Greco-Roman ruins, had around 25,000 inhabitants in the 3rd century, but its population had dropped to 10,000 inhabitants at the end of the 6th century, weakening the city in the face of health crises. Located in the Decapolis region, Jerash served as a commercial, administrative and religious center, connected to the major networks of the Eastern Mediterranean, from Egypt to Syria and Anatolia. This economic and cultural connectivity has fostered the city’s prosperity, but also made it vulnerable to the rapid spread of disease.
It is in this context that excavations have uncovered, in the Jerash hippodrome, a massive burial containing around 230 individuals, dating from the mid-6th to early 7th centuries.
Biological traces that tell a human story
To understand the profile of these victims, researchers combined archaeological observations, stable isotope analyzes and studies of ancient DNA. Analysis of bone collagen showed that individuals primarily consumed plant resources typical of the region, while oxygen in tooth enamel showed much wider variation than observed in other long-term resident populations in the Levant.
These differences suggest that those buried at Jerash had grown up in very diverse water environments, revealing the coexistence of socially and geographically heterogeneous populations.
Genetic analysis confirmed the presence of a single strain of Yersinia pestis – more commonly known as the Plague – attesting to a synchronous epidemic event (an epidemic which occurs over the same period, simultaneously, affecting a group of people at the same time, rather than in successive waves spread out over time). Additionally, the recovered data reinforces the idea that the pandemic brought together a diverse and mobile population into a single mass grave, providing a rare insight into demographic structure and urban vulnerability at the time.
Revealing burial conditions
The archaeological excavation showed that the bodies had been deposited quickly, without prolonged burial arrangements and without traces of violence. The individuals were piled up on layers of pottery shards, in an abandoned public space at the racecourse, reflecting the urgency and brutality of the epidemic. This mode of deposition, densely organized but devoid of rituals, recalls the catastrophic pits of the medieval plague, but Jerash constitutes an exceptionally well preserved example for late antiquity.
According to The Guardian, Rays HY Jiang, associate professor at the University of South Florida’s College of Public Health and lead author of the study, explains: “Pandemics are not just biological events, they are social events. By connecting biological evidence from the bodies to the archaeological context, we can see how disease actually affected individuals in their social and urban environments.”
A window on urban life and mobility
The study reveals that the population affected by the plague in Jerash was diverse, including men, women, adolescents and adults of working age. According to the authors of the study, people, generally mobile and dispersed, were brought together by the crisis. Pandemics thrive in densely populated cities, where travel and environmental changes promote disease transmission.
The combination of archaeological, isotopic and genetic data allows us to understand how the city experienced the epidemic: a socially heterogeneous population, accustomed to mobility, suddenly struck by the disease and unable to flee. This multidisciplinary approach provides a valuable framework for studying community structure, vulnerability, and the lived experience of pandemics in late antiquity.
Researchers highlight analogies with contemporary health crises, notably the Covid-19 pandemic. Mobility, the unpredictability of the spread and the forced groupings of vulnerable populations are found throughout the centuries.
A unique testimony for the Eastern Mediterranean
With this mass grave, Jerash becomes the first site in the Near East where the Plague of Justinian is confirmed both archaeologically and genetically. The study entitled “Bioarchaeological signatures during the Plague of Justinian (541–750 CE) in Jerash, Jordan» thus offers a solid basis for reconstructing the demographic and epidemiological landscape of the early Mediterranean Middle Ages, transforming genetic and isotopic data into a tangible human narrative.
This discovery highlights the scale and brutality of the first pandemic in Mediterranean history, and allows us to better understand how ancient urban societies faced major health crises, by combining biology, archeology and history.
