The Plague of Justinian Opens the First Yersinia Pestis Pandemic
Ancient DNA from Jerash and across Western Europe confirms the same bacterium behind the Black Death caused history's first recorded plague pandemic
Quick facts
- Pathogen
- Yersinia pestis, confirmed by ancient DNA
- Also known as
- The First Plague Pandemic
- Duration
- 541 to about 750 CE
- Reported peak toll
- Up to 10,000 deaths a day in Constantinople, per Procopius
- Key evidence
- Y. pestis DNA recovered from Jerash, Jordan, and burial sites in Britain, France, Germany, and Spain
What happened
In 541 CE an epidemic began in the Byzantine Empire, reported first at the Egyptian port of Pelusium and reaching the capital Constantinople in 542, where the historian Procopius recorded it striking as many as 10,000 people a day at its worst under Emperor Justinian I, who caught the disease himself and survived. What became known as the First Pandemic recurred in waves across the Mediterranean and Europe for roughly two centuries, until about 750. For most of history the pathogen was inferred only from written symptoms; that changed when ancient DNA studies recovered Yersinia pestis genetic material from human teeth in a mass grave beneath the Roman hippodrome at Jerash, Jordan, near the outbreak's likely epicenter, and from burial sites across Britain, France, Germany, and Spain, directly confirming the bacterium responsible.
Why it matters
This is the same organism, Yersinia pestis, that would cause the Black Death eight centuries later and still causes isolated plague cases today, making Justinian's outbreak the first of three historically documented pandemics from a single bacterial species. The genomic work also found the strains did not descend in a single line into later pandemics; separate plague lineages emerged independently in different eras, reshaping how historians think about plague's long-term persistence in nature rather than one continuous chain of transmission.
How we know
Researchers used a two-stage ancient DNA screening method, qPCR targeting the Yersinia pestis pla gene followed by targeted genome capture, to recover eight high-coverage genomes from Western European burials and additional genomes from Jerash. This is direct molecular confirmation, not textual inference, published in PNAS and related studies.
Sources
- Euronews. History's first pandemic: Ancient DNA solves mystery of what caused 1,500-year-old epidemic · General sourceeuronews.com · Cited as a "news" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- PNAS via PMC (National Library of Medicine). Ancient Yersinia pestis genomes from across Western Europe reveal early diversification during the First Pandemic (541-750) · Peer-reviewed (author-declared)pmc.ncbi.nlm.nih.gov · Cited as a "journal" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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Related timelines
- The Byzantine Empire → · See how the plague struck at the height of Justinian's reign and reshaped the empire's finances and ambitions.