One of the most important questions about the Black Death, the pandemic that caused millions of deaths in the 14th century, is where and when did it begin. Now a new study is pointing to a trading community in Lake Issyk Kul, in what is now Kyrgyzstan, as the place where the pandemic started in the years 1338 and 1339.
The research, published in the journal Nature, comes from a multidisciplinary team of scientists and researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, the University of Tübingen, and the University of Stirling.
The origins of this pandemic have long been debated. One of the most popular theories has supported its source in East Asia, specifically in China. However, the only so-far available archaeological findings come from Central Asia, close to Lake Issyk Kul, which lies east of Bishkek, the capital of Kyrgyzstan. These findings show that an epidemic devastated a local trading community in the years 1338 and 1339. Specifically, excavations that took place in the late 1880s revealed tombstones indicating that individuals died in those years of an unknown epidemic or “pestilence”. Since their first discovery, the tombstones inscribed in Syriac language, have been a cornerstone of controversy among scholars regarding their relevance to the Black Death of Europe.
In this study, an international team of researchers analysed ancient DNA from human remains as well as historical and archaeological data from two sites that were found to contain “pestilence” inscriptions. The team’s first results were very encouraging, as DNA from the plague bacterium, Yersinia pestis, was identified in individuals with the year 1338 inscribed on their tombstones. “We could finally show that the epidemic mentioned on the tombstones was indeed caused by plague”, says Philip Slavin, one of the senior authors of the study and historian at the University of Stirling.
But could this have been the origin of the Black Death? Researchers have previously associated the Black Death’s initiation with a massive diversification of plague strains, a so-called Big Bang event of plague diversity. But the exact date of this event could not be precisely estimated, and was thought to have happened sometime between the 10th and 14th centuries. The team now pieced together complete ancient plague genomes from the sites in Kyrgyzstan and investigated how they might relate with this Big Bang event. “We found that the ancient strains from Kyrgyzstan are positioned exactly at the node of this massive diversification event. In other words, we found the Black Death’s source strain and we even know its exact date [meaning the year 1338]”, says Maria Spyrou, lead author and researcher at the University of Tübingen.
But where did this strain come from? Did it evolve locally or did it spread in this region from elsewhere? Plague is not a disease of humans; the bacterium survives within wild rodent populations across the world, in so-called plague reservoirs. Hence, the ancient Central Asian strain that caused the 1338-1339 epidemic around Lake Issyk Kul must have come from one such reservoir. “We found that modern strains most closely related to the ancient strain are today found in plague reservoirs around the Tian Shan mountains, so very close to where the ancient strain was found. This points to an origin of Black Death’s ancestor in Central Asia”, explains Johannes Krause, senior author of the study and director at the Max Planck Institute for Evolutionary Anthropology.
The study demonstrates how investigations of well-defined archaeological contexts, and close collaborations among historians, archaeologists and geneticists can resolve big mysteries of our past, such as the infamous Black Death’s origins, with unprecedented precision.
“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,” adds Philip Slavin.
The article, “The source of the Black Death in fourteenth-century central Eurasia,” by Maria A. Spyrou, Lyazzat Musralina, Guido A. Gnecchi Ruscone, Arthur Kocher, Pier-Giorgio Borbone, Valeri I. Khartanovich, Alexandra Buzhilova, Leyla Djansugurova, Kirsten I. Bos, Denise Kühnert, Wolfgang Haak, Philip Slavin and Johannes Krause, appears in Nature. Click here to read it.
Top Image: View of the Tian Shan mountains. Studying ancient plague genomes, researchers traced the origins of the Black Death to Central Asia, close to Lake Issyk Kul, in what is now Kyrgyzstan. Photo ©Lyazzat Musralina