Pests and Their Impacts on Humans : An Environmental History of Infectious Diseases during Mongol Invasions in East Asia

Korea experienced a severe mortality crisis under Mongol rule during the thirteenth and fourteenth centuries. Scholars have examined the high death toll during the Mongol Invasions of Korea (1231–1259), arguing epidemics exacerbated the wartime conditions. By closely scrutinizing historical documents on epidemics and pests, this article situates epidemics within a broader environmental context that encompasses not only Korea but also Song China, Japan, and Vietnam in the thirteenth century. Although there is no direct evidence to suggest the same pathogens for the parallel of epidemics across East Asia, these countries shared the similarities of being invaded by the Mongols, and such vulnerable wartime conditions and the climate anomalies of the thirteenth century could be the main environmental variables to precipitate these widespread outbreaks in these regions. A key question remains regarding the type of wartime infectious diseases. This article adopts environmental perspectives to explore whether the thirteenth- century outbreaks in East Asia, especially Korea, might be connected to the Black Death or could potentially be typhus—commonly seen in warfare or something else. Without ruling out the possibility that the Mongol invasions may have transported new pathogens to the Korean peninsula, I argue that the environmental legacy of these invasions was to create a new cultural disease environment in Korea. Korean historical records frequently mention the presence of rodents and lice, likely transported by the Mongol cavalry, which posed a threat to daily Korean life during the prolonged Mongol invasion periods, suggesting the possible outbreaks of plague or typhus. Furthermore, the Mongol nomadic culture, with its affinity to livestock like horses, cattle, and sheep, also created another environment conducive to bacteria transmission. Even after the invasions ended, the established disease environments and continuous movements of people continued to affect the Korean peninsula and its animal and human inhabitants during the thirteenth and fourteenth centuries.