The Black Death is considered the deadliest plague in human history. But despite years of research, its geographic and chronological origins remain largely a mystery.
Now, a new study of ancient DNA from bubonic plague victims claims the disease has been traced back to 1338 in present-day Kyrgyzstan.
Researchers obtained ancient DNA traces of the Yersinia pestis plague bacterium from the teeth of three women buried in a medieval Nestorian Christian community in the Chu Valley near Issyk Kul Lake, which perished in 1338-1339.
The earliest deaths recorded elsewhere in the pandemic were in 1346.
Reconstruction of the pathogen’s genome showed that this strain not only caused the Black Death, which affected Europe, Asia, the Middle East and North Africa, but also gave rise to most plague strains present today.
Researchers say the bubonic plague spread to the Mediterranean Sea via the old Silk Road trade route, before causing a nearly 500-year-long wave of killer diseases called the second plague pandemic.
Between 1346 and 1353 the Black Death affected the Middle East and Europe, killing 200 million people, annihilating half of Londoners and up to 60 percent of Europeans.
Researchers believe that the Black Death first began in Kyrgyzstan in the late 1330s. They analyzed ancient DNA taken from the teeth of skeletons discovered in cemeteries. The picture is a headstone inscription from the Chu-Valley region in Kyrgyzstan. The inscription is translated as: ‘This is the tomb of the believer Sanamak. [He] died of epidemic [bubonic plague],
In the picture is an excavation of the Karazygach site, in the Chu-Valley of Kyrgyzstan, within the foothills of the Tian Shan Mountains. This was done between 1885 and 1892.
The Silk Road was an underground route for caravans carrying goods back and forth from China through the magnificent cities of Central Asia to points including the Byzantine capital Constantinople and Persia.
It can also serve as a route of death if the pathogen gets aboard the caravan.
‘Several different hypotheses suggest that the epidemic originated in East Asia, particularly China, Central Asia, India, or even where it first occurred in the Black Sea and Caspian Sea regions in 1346. There was a documented outbreak. could be near. ,’ said Maria Spirou, an archaeologist at the University of Tübingen in Germany and lead author of the study.
‘We know that trade was a decisive factor in the spread of plague in Europe during the onset of the Black Death. It is reasonable to speculate that similar processes determined the spread of the disease from Central Asia to the Black Sea between 1338 and 1346.’
Researchers have previously linked the onset of the Black Death with a large-scale diversification of plague strains, the so-called ‘Big Bang’ of plague diversity.
But the exact date of this event could not be estimated, and it is believed to have occurred between the 10th and 14th centuries.
The research team has now pieced together a complete ancient plague genome from Kyrgyzstan sites and examined how they may be related to the ‘Big Bang’ event.
Dr Maria Spirou from the University of Tübingen and first author of the study, said: ‘We found that the ancient strains of Kyrgyzstan are located at the node of this huge diversification event.
‘In other words, we have found the source of the Black Death and we also know its exact date.’
The Black Death is believed to have arrived in Britain in 1348 on a ship landing off the Dorset coast from Gascony in France before rapidly spreading across the country.
Picture, depicting the burial of plague victims during the Black Death. Devastating bubonic plague epidemic ravaged Europe from 1346 to 1353
Researchers analyzed ancient DNA (aDNA) taken from the teeth of skeletons discovered in cemeteries near Issyk Kul Lake in the Tian Shan region of Kyrgyzstan (shown)
A view of the Tian Shan mountains. Studying ancient plague genomes, researchers trace the origins of the Black Death to Central Asia, close to Lake Issyk Kul in what is now Kyrgyzstan.
The research teams behind the new study were from the University of Stirling in Scotland and the Max Planck Institute and the University of Tübingen in Germany.
They analyzed ancient DNA (aDNA) taken from the teeth of skeletons discovered in cemeteries near Issyk Kul Lake in the Tian Shan region of Kyrgyzstan.
Scientists were attracted to these sites after identifying a huge increase in the number of burials in 1338 and 1339, according to historian Dr Philip Slavin of the University of Stirling, who helped make the discovery.
They found that the cemeteries in Kara-Jigach and Burana, already excavated in the late 1880s, had about 30 skeletons removed from the graves, but they could not trace them and analyze DNA taken from the teeth of seven individuals. were unable to. can do.
The sequencing, which determined the DNA structure, showed that the three individuals carried Yersinia pestis, a bacterium linked to the start of the Black Death outbreak, before arriving in Europe.
“Our study is one of the biggest and most fascinating questions in history to determine when and where some of the most infamous and notorious killers of humans began,” said Dr. Slavin said.
Part of their work involved studying the historical diaries of the original excavations to match individual skeletons to their headstones, carefully translating the inscriptions, which were written in the Syriac language.
The Silk Road is a complex system of trade routes connecting East and West Eurasia through its arid continental interior. Its name is derived from the lucrative trade of silk which dates back to around 200BC. from across continents
Dr Spirou said: ‘Despite the risk of environmental contamination and no guarantees that the bacteria would be able to be preserved, we were able to sequence aDNA taken from seven individuals extracted from two of these graveyards.
‘The most exciting thing is that we found DNA of the plague bacterium in three individuals.’
He explained that the plague is not a disease of humans; The bacteria survive in so-called plague reservoirs within wild rodent populations around the world.
Researchers say the ancient Central Asian strain that caused the 1338-1339 epidemic around Issyk Kul lake may have come from one such reservoir.
Co-senior author Professor Johannes Krauss, from the Max Planck Institute, said: ‘We found that modern strains most closely related to the ancient strain today are found in plague reservoirs around the Tian Shan mountains, where the ancient strain was. found it.’
He added: ‘This points to an ancestral origin of the Black Death in Central Asia.’
The findings were published in the journal Nature,