University of Tübingen: Origin of the Black Death identified

The Black Death, the largest pandemic in human history, was caused by the bacterium Yersinia pestis and ravaged Europe between 1346 and 1353. It had immense demographic and societal impacts, but its origins have long been a mystery. Using analyzes of ancient Y. pestis genomes, a multidisciplinary team including researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, the University of Tübingen and the University of Stirling in the UK has now succeeded in pinpointing the origin of the plague pandemic of the time located in Central Asia.

In 1347, the plague reached the Mediterranean for the first time via merchant ships from the Black Sea from the settlement areas of the “Golden Horde”, part of the Mongol Empire. The disease quickly spread across Europe, the Middle East, and North Africa, killing up to 60 percent of the population in a single major outbreak that became known as the Black Death. This first wave of infection spread into a 500-year pandemic known as the Second Plague Pandemic, which lasted into the early 19th century.

The origins of the Second Plague Pandemic have long been debated among experts. One of the most popular theories is that it may have originated in East Asia, specifically China. However, this theory is contradicted by archaeological finds from Central Asia, which come from an area near Lake Issyk-Kul in modern-day Kyrgyzstan, in the foothills of the Tian Shan Mountains. They provide evidence of an outbreak of plague within a local trading community in 1338 and 1339. Excavations nearly 140 years ago have uncovered tombstones with inscriptions indicating that these people fell victim to an unknown epidemic. Since their discovery, the tombstones, which are inscribed in Syriac-Aramaic, have been the subject of controversy in specialist circles in Europe due to their significance for the Black Death.

In the present study, an international research team analyzed ancient DNA from human remains as well as historical and archaeological data from two sites where plague inscriptions were found. The first results were already encouraging: the researchers were able to detect DNA from the plague bacterium Yersinia pestis in people who, according to the gravestone inscription, died in 1338. “We were finally able to prove that the epidemic mentioned on the tombstones was actually caused by the plague,” says Phil Slavin, one of the study’s lead authors and a historian at the University of Stirling.

Research team identifies the origin tribe of the Black Death
Could the research team have traced the origins of the Black Death? So far, the Black Death outbreak has been associated with a massive diversification of plague strains, a so-called Big Bang of plague diversity. However, the time of this event could not be determined exactly – it was previously classified as between the 10th and 14th centuries. The research team has now assembled complete ancient plague genomes from sites in Kyrgyzstan and investigated how they could be linked to this Big Bang event. “We found that the ancient tribes from Kyrgyzstan are right at the nexus of this massive diversification event. So we actually succeeded

“Plague” inscription from the Chu Valley region of Kyrgyzstan. Translated it says: “In the year 1649 [= 1338 CE], in the year of the tiger. This is the tomb of the devotee Sanmaq. [He] died of the plague”.
“Plague” inscription from the Chu Valley region of Kyrgyzstan. Translated it says: “In the year 1649 [= 1338 CE], in the year of the tiger. This is the tomb of the devotee Sanmaq. [He] died of the plague”.

But where did this tribe come from? Did it develop locally or was it introduced to the region and then spread? The plague is not a disease of human origin; the bacterium Y. pestissurvives in wild rodent populations around the world – in so-called plague reservoirs. So the ancient Central Asian tribe that caused the epidemic of 1338-1339 at Lake Issyk-Kul must have come from such a reservoir. “Today, we find modern tribes most closely related to the ancient tribe in plague reservoirs around the Tian Shan Mountains, very close to where this ancient tribe was found. So the ancestor of the Black Death appears to have originated in Central Asia,” explains Johannes Krause, lead author of the study and Director at the Max Planck Institute for Evolutionary Anthropology.

The study also shows that multidisciplinary teams of historians, archaeologists and geneticists can play a key role in solving major mysteries of our past and answering scientific questions – such as the origins of the infamous Black Death – with unprecedented precision.