TAMPA, Fla. (Jan. 20, 2026) -- "A plague is upon us'' must have been a common phrase in ancient Jordan, where countless people perished from a mysterious malady that would shape both a society and an era of civilization.
Now, an interdisciplinary team of University of South Florida experts is learning more about the Plague of Justinian and its consequences during that early time. Led by Rays H. Y. Jiang , an associate professor in the College of Public Health , the team recently completed a third in a series of scholarly papers focusing on the first-known outbreak of bubonic plague in the Mediterranean world.
The paper " Bioarchaeological signatures during the Plague of Justinian (541–750 CE) in Jerash, Jordan " is in print at the Journal of Archaeological Science. It adds to the historical record on what caused the devastating outbreak that killed millions within the Byzantine Empire.
"We wanted to move beyond identifying the pathogen and focus on the people it affected, who they were, how they lived and what pandemic death looked like inside a real city,'' Jiang said.
During the Plague of Justinian, the people affected lived in diverse and often unconnected communities. But the plague brought them together in death, with countless bodies deposited rapidly atop layers of pottery debris in an abandoned civic space − the focal point of this recent research.
Jiang was principal investigator for the study, with colleagues from USF's Genomics, Global Health Infectious Disease Research Center and the departments of anthropology, molecular medicine and history. Additional insights came from archaeologist Karen Hendrix at Sydney University Australia and a DNA lab at Florida Atlantic University . While their first two papers focused primarily on Yersinia pestis, a pathogen that causes deadly forms of plague, the new research examined its short and long-term impact on an ancient society – and even what it might mean today.
"The earlier stories identified the plague organism,'' Jiang said. "The Jerash site turns that genetic signal into a human story about who died and how a city experienced crisis.''
While historical sources describe widespread plague in the Byzantine world, many proposed mass burials have remained speculative. Jerash is the first site where a plague mass grave has been confirmed both archaeologically and genetically.
The authors describe it as a single mortuary event, fundamentally different from normal civic cemeteries that grow in size over time. At Jerash, hundreds of bodies were deposited within days. This finding changes perceptions about the First Pandemic in two important ways: It provides direct evidence of large-scale human mortality and offers insight into how people moved, lived and became vulnerable within ancient cities.
The mass grave also helps resolve a long-standing puzzle: Why history and genetics show that people moved and mixed over time, while other evidence makes ancient communities appear mostly local. Trade, migration and empires brought people together across the Middle East, yet most burials suggest people grew up where they were buried.
Jerash shows both can be true. Migration often happened gradually over generations and was usually diluted within everyday communities, making it hard to detect in normal cemeteries. During a crisis, however, mobile populations were suddenly concentrated together, allowing long-term patterns of movement to become visible in a single moment.
The evidence suggests that the individuals buried at Jerash were part of a mobile population embedded within the broader urban community of ancient Jordan, normally dispersed across the landscape but brought together in a single mass grave by crisis.
"By linking biological evidence from the bodies to the archaeological setting, we can see how disease affected real people within their social and environmental context,'' Jiang said. "This helps us understand pandemics in history as lived human health events, not just outbreaks recorded in text.''
The research team is helping reshape the understanding not only of how pandemics are born and spread, but their impact on human life and civic responses. They thrive through densely populated cities, travel and environmental change, just as pathogens of today.
"Pandemics aren't just biological events, they're social events, and this study shows how disease intersects with daily life, movement and vulnerability,'' Jiang said. "Because pandemics reveal who is vulnerable and why, those patterns still shape how disease affects societies today.''
In addition to Jiang, the USF team on the three papers included:
- Swamy R. Adapa, research and development scientist, Department of Global Environmental and Genomic Health Sciences , COPH
- Andrea Vianello, PhD, visiting research fellow, Department of Anthropology, College of Arts and Sciences
- Elizabeth Remily-Wood, proteomics core director, Department of Molecular Medicine, Morsani College of Medicine
- Gloria C. Ferreira, PhD, professor, Department of Molecular Medicine, Morsani College of Medicine and College of Arts and Sciences
- Michael Decker, PhD, Maroulis Professor of Byzantine History and Orthodox Religion, Department of History, College of Arts and Sciences
- Robert H. Tykot, PhD, professor, Department of Anthropology, College of Arts and Sciences.
