The “Black Death” is the name given by modern historians to the great pandemic of plague that ravaged parts of Asia, the Middle East, North Africa, and Europe in the middle of the fourteenth century. Contemporaries knew it by many names, including the “Great Pestilence,” the “Great Mortality,” and the “Universal Plague.” This epidemic was the first and most devastating of the second known cycle of widespread human plague, which recurred in waves, sometimes of great severity, through the eighteenth century. Some of the later and milder “plagues” in this period seem to have also involved other diseases, including influenza, smallpox, and dysentery. Nonetheless almost all historians agree, on the basis of contemporary descriptions of its symptoms, that the Black Death should be identified as a massive epidemic of plague, a disease of rodents, caused by the bacillus Yersinia pestis, that can in the case of massive epizootics be transmitted to human beings by fleas. Although the Black Death manifested itself most commonly as bubonic plague, it also appeared at various times and places in its primary pneumonic and septicemic forms.

History and Geography

The geographic origins and full extent of the Black Death are still unclear. The earliest indisputable evidence locates it in 1346 in the cities of the Kipchak Khanate of the Golden Horde, north and west of the Caspian Sea. Until recently, most historians have claimed, based on Arabic sources, that the epidemic originated somewhere to the east of the Caspian, in eastern Mongolia or Yunnan or Tibet, where plague is enzootic in various populations of wild rodents.