The origins of the deadly Black Death have been discovered more than 600 years after it entered the human population, scientists have said.
The medieval, bubonic plague was first recorded in the 14th century and was the start of a near 500-year-long wave of killer diseases termed the Second Plague Pandemic.
The Black Death killed millions and was considered one of the largest infectious disease catastrophes in human history.
Despite years of research, the geographic and chronological origin of the disease remained a mystery.
Our study puts to rest one of the biggest and most fascinating questions in history and determines when and where the single most notorious and infamous killer of humans began
Dr Philip Slavin, University of Stirling
But researchers said they believe the Black Death first originated in North Kyrgyzstan in the late 1330s.
The team, from Scotland’s University of Stirling and Germany’s Max Planck Institute and University of Tubingen, analysed ancient DNA (aDNA) taken from the teeth of skeletons discovered in cemeteries near Lake Issyk Kul in the Tian Shan region of Kyrgyzstan.
They were drawn to these sites after identifying a huge spike in the number of burials there in 1338 and 1339, according to University of Stirling historian Dr Philip Slavin, who helped make the discovery.
The team found the cemeteries, at Kara-Djigach and Burana, had already been excavated in the late 1880s, with about 30 skeletons taken from the graves, but were able to trace them and analyse DNA taken from the teeth of seven individuals.
The sequencing, which determines the DNA structure, showed three individuals carried Yersinia pestis, a bacterium which is linked to the beginning of the Black Death outbreak before it arrived in Europe.
“Our study puts to rest one of the biggest and most fascinating questions in history and determines when and where the single most notorious and infamous killer of humans began,” Dr Slavin said.
Part of his work involved studying the historic diaries of the original excavations in order to match the individual skeletons to their headstones, carefully translating the inscriptions, which were written in the Syriac language.
Dr Maria Spyrou, of the University of Tubingen, and the first author of the study, said: “Despite the risk of environmental contamination and no guarantee that the bacteria would have been able to be preserved, we were able to sequence aDNA taken from seven individuals unearthed from two of these cemeteries.
“Most excitingly, we found aDNA of the plague bacterium in three individuals.”
Professor Johannes Krause of the Max Planck Institute for Evolutionary Anthropology in Leipzig, added: “Just like Covid, the Black Death was an emerging disease, and the start of a huge pandemic that went on for some 500 years.
“It’s very important to understand actually in what circumstances did it emerge.”
The origins of the Black Death have been debated by historians for centuries, and postulated by medieval chroniclers ever since its appearance in Europe, the Middle East and North Africa 675 years ago.
The research study, The source of the Black Death in 14th-century central Eurasia, has been published in the journal Nature.