Ancient Jerash Mass Grave Unveils Insights into First Recorded Pandemic

A recent study published in the Journal of Archeological Science examines the victims of a 7th-century plague in the ancient city of Jerash, located in modern-day Jordan. During the outbreak, workshops under the city's Hippodrome were repurposed as a mass grave, containing hundreds of bodies.

The Groundbreaking Research

The research, led by University of South Florida geneticist Rays Jiang, involved a multidisciplinary team of experts from archaeology, molecular genetics, anthropology, and chemistry. Their extensive work provides crucial insight into what is considered the first historically recorded pandemic: the Plague of Justinian. This devastating pandemic affected the Mediterranean Basin, West Asia, and Northern Europe between 541 and 750 CE.

Understanding the Pathogen

Analysis of plague microbes from the Jerash bodies indicated extreme similarity across samples. This finding suggests the bacteria, identified as Yersinia Pestis, spread rapidly and caused quick fatalities before significant mutation could occur.

This specific strain of Yersinia Pestis was responsible for all identified victims in the grave, highlighting its swift and deadly impact.

Jerash, strategically located on a major trade route within the Eastern Roman Empire, experienced multiple waves of the plague. By around 650 CE, the city's population had decreased to approximately 10,000 residents. Yersinia Pestis has a high mortality rate, ranging from 60% to 100% without treatment.

Research Methodology

Researchers extracted samples from human teeth discovered during 1980s excavations. They conducted mitochondrial DNA sequencing and stable isotope analysis. Tooth dentine, formed in early childhood, retains isotopic markers like carbon, nitrogen, and oxygen, which allow for the reconstruction of an individual's childhood diet and geographical origins.

Diverse Origins of Victims

The mass grave contained approximately 230 victims, including men, women, and children. DNA analysis indicated ancestral ties to diverse regions such as central Africa, eastern Europe, and Anatolia. This genetic data was strongly supported by isotope analysis, which demonstrated varied childhood diets and geographical origins among the victims.

The team noted that these individuals did not appear to be local residents, suggesting they were highly mobile populations such as visiting merchants, foreign workers, or enslaved people.

This finding highlights a demographic layer often underrepresented in ancient cemeteries, which includes economic migrants, itinerant laborers, and displaced persons.

Expert Perspective

Nükhet Varlık, an ancient pandemics expert at Rutgers University not involved in the study, commented that the research aligns with historical responses to pandemics.

"Following initial plague waves, cities often required new labor sources, attracting immigrants who then became vulnerable to subsequent outbreaks."

Preservation and Lasting Insights

An earthquake in 659 CE caused the Hippodrome structure to collapse, effectively sealing the mass grave and preserving the remains for centuries. The study emphasizes the long-term presence of plague and the ongoing importance of managing its spread and containment in historical and modern contexts.