Researchers confirmed Yersinia pestis, later behind the Black Death, caused the Justinian Plague 1,500 years ago.
They traced the bacterium to its epicentre for the first time, solving a centuries-old mystery.
Experts found Yersinia pestis in a mass grave beneath Jerash’s ruins in Jordan, providing direct biological proof.
Lead author Rays HY Jiang said the discovery offers the first genetic evidence of the pandemic’s spread.
How the Plague Spread Across the Empire
The Justinian Plague began in 541 CE, sweeping through the Byzantine Empire and eastern Mediterranean.
Historians estimate it killed between 15 and 100 million people over two centuries of recurring outbreaks.
Scientists confirmed Yersinia pestis caused the pandemic, the same bacterium that later triggered the Black Death.
Fleas on rodents, especially rats living near humans, transmitted the bacterium, while pneumonic forms spread directly between people.
Unlocking Ancient DNA Evidence
Researchers analyzed eight human teeth from burial chambers beneath Jerash’s Roman hippodrome using advanced DNA techniques.
They found almost identical Yersinia pestis strains, confirming the bacterium circulated between 550 and 660 AD.
The DNA evidence supports historical accounts of rapid, deadly outbreaks overwhelming urban centres like Jerash.
Plague Threat Persists Through Millennia
Yersinia pestis circulated among humans long before the Justinian outbreak, according to related studies.
Later pandemics, including the Black Death and modern cases, arose independently from animal reservoirs.
Jiang warned the plague continues to evolve, and containment measures cannot fully eliminate its threat today.
