The Black Death originated in Central Asia, specifically in what is now Kyrgyzstan. Recent research based on ancient DNA and archaeological evidence places the ancestral strain of the Black Death bacterium, Yersinia pestis, near the Tien Shan Mountains close to Lake Issyk Kul in Kyrgyzstan. An epidemic there in 1338-1339, just years before the pandemic began in Europe, was caused by this strain, which then gave rise to the vast majority of plague strains circulating today. From Central Asia, the disease spread westward, reaching Europe via trade routes and the Black Sea region by 1347.

This Central Asian origin aligns with findings of tombstones from 1338-1339 in Kyrgyzstan marking deaths from "pestilence," confirming the site as an early hotspot of the plague before its spread to Europe.