The Black Death

The Plague in Asia: The Black Death Before Europe

The Black Death is remembered primarily as a European catastrophe, but the pandemic began in Asia and devastated Asian populations years before it reached the shores of the Mediterranean. The disease emerged from the rodent reservoirs of the Central Asian steppe in the 1330s and spread eastward through China, southward through India, and westward along the trade routes that connected the Mongol khanates to the wider world. By the time the plague arrived in Europe in 1347, it had already killed millions across Asia.

The Central Asian Epicentre

The Tian Shan mountains, straddling the borders of modern Kyrgyzstan, Kazakhstan, and western China, have long been identified as a natural reservoir for Yersinia pestis. The high-altitude grasslands of the region support dense populations of marmots, gerbils, and other burrowing rodents that serve as the bacterium’s primary hosts. Epizootic outbreaks among these rodent populations occur periodically, driven by climatic fluctuations that affect rodent density and flea reproduction rates.

The most compelling evidence for the pandemic’s origins in this region comes from two Nestorian Christian cemeteries near Lake Issyk-Kul in Kyrgyzstan — Kara-Djigach and Burana — where tombstones dated to 1338 and 1339 record an unusual spike in deaths attributed to “pestilence” (mawtānā in Syriac). A 2022 study led by Maria Spyrou and Johannes Krause recovered Y. pestis DNA from the teeth of individuals buried in these cemeteries, confirming that the ancestral strain of the Black Death lineage was present in the region at precisely this time. This finding provides the earliest direct evidence of the pandemic strain and locates its emergence within the commercial and political networks of the Chagatai Khanate.

The communities around Lake Issyk-Kul were not isolated. They were integrated into the trade networks of the Mongol Empire, with merchants, soldiers, and travellers passing through regularly. The Nestorian Christians who buried their dead at Kara-Djigach were part of a wider community that stretched from Syria to China, connected by the same routes that would carry the plague westward.

The Plague in China

China in the 1330s and 1340s was ruled by the Yuan dynasty, established by Kublai Khan in 1271. The empire was vast, populous, and commercially vibrant, with cities like Hangzhou, Quanzhou, and Dadu (modern Beijing) ranking among the largest in the world. The trade routes connecting China to Central Asia were heavily trafficked, and the movement of goods, soldiers, and administrators between the Yuan court and the western khanates provided ample opportunity for the bacterium to travel.

Chinese historical sources from the late Yuan period record a series of devastating epidemics that struck various regions of the empire between the 1330s and the 1350s. The Yuan Shi (History of the Yuan Dynasty), compiled after the dynasty’s fall in 1368, describes outbreaks of disease in Hebei province in 1331 that reportedly killed a majority of the population. Further epidemics are recorded in the 1340s and 1350s, coinciding with the floods, famines, and civil unrest that ultimately brought down the dynasty.

The identification of these Chinese epidemics as plague specifically is complicated by the nature of the sources. Chinese medical terminology did not distinguish between different epidemic diseases with the precision of modern nosology, and the terms used — yi (epidemic), da yi (great epidemic), or wen yi (warm epidemic) — could refer to a range of infectious diseases. Some scholars, notably the historian Timothy Brook, have argued that the Chinese epidemics of the 1330s may have been caused by other pathogens, such as typhus or smallpox, rather than Y. pestis. Others, including the epidemiologist Ole Benedictow, maintain that the scale and characteristics of the mortality are consistent with plague.

Regardless of the specific pathogen, the demographic impact was severe. China’s population, which had reached approximately 120 million under the Song dynasty in the early thirteenth century, fell dramatically during the Mongol conquest and continued to decline through the Yuan period. By the time the Ming dynasty was established in 1368, the population had fallen to perhaps 60–80 million. Epidemic disease was one factor among several — warfare, famine, and displacement — that drove this decline, but it was a significant one.

The Plague in India

The Indian subcontinent’s connections to the Central Asian plague zone ran through the mountain passes of Afghanistan and the maritime routes of the Indian Ocean. The Delhi Sultanate, which ruled much of northern India in the mid-fourteenth century, maintained close commercial and diplomatic ties with Central Asia, Persia, and the Middle East. Merchants from the Indian ports of Gujarat and the Malabar Coast traded extensively with the Persian Gulf and the Red Sea.

Direct evidence for plague in fourteenth-century India is sparse. The Moroccan traveller Ibn Battuta, who visited India in the 1340s, does not mention plague in his account, though his itinerary may have avoided the worst-affected areas. Some historians have suggested that the relatively warm climate of the Indian subcontinent may have limited the spread of Y. pestis, which thrives in cooler conditions, though this argument is weakened by the devastating impact of the Third Pandemic on India in the late nineteenth and early twentieth centuries, when plague killed millions in Bombay, Calcutta, and other Indian cities.

The absence of clear evidence does not necessarily mean the absence of plague. The Indian subcontinent’s historical records from this period are fragmentary, and epidemic diseases may have been recorded in terms that do not correspond to modern diagnostic categories. The trade connections between India and the plague-affected regions of Central Asia and the Middle East were extensive enough to make transmission highly probable.

The Mongol Khanates and the Plague

The four Mongol khanates that divided the empire in the fourteenth century — the Yuan dynasty in China, the Chagatai Khanate in Central Asia, the Ilkhanate in Persia, and the Golden Horde in the Pontic steppe — were all affected by the pandemic, though the evidence varies in quality.

The Chagatai Khanate, which controlled the heartland of the plague’s Central Asian origins, was already fragmenting by the 1340s. The Issyk-Kul cemetery evidence suggests that plague struck the region in 1338–1339, and the political instability that followed may have been exacerbated by demographic losses. The rise of Timur (Tamerlane) in the 1360s and 1370s, which reshaped the political geography of Central Asia, occurred in a landscape already scarred by plague.

The Ilkhanate in Persia collapsed in 1335, following the death of the last effective ruler, Abu Sa’id. While the immediate cause of his death is uncertain, some sources attribute it to an epidemic that also struck his army. The political fragmentation that followed left Persia divided among competing warlords, and the subsequent decades saw repeated outbreaks of disease that further weakened the region. The historian Hamdallah Mustawfi Qazwini, writing in the 1340s, described widespread mortality in the cities of western Iran, though he did not identify the disease specifically.

The Golden Horde, which controlled the Pontic steppe and the Crimean peninsula, was the khanate most directly involved in the transmission of plague to Europe. The siege of Caffa in 1346, in which the army of Jani Beg was decimated by plague, occurred within the Golden Horde’s territory. The khanate’s commercial connections to the Italian trading colonies on the Black Sea coast provided the direct conduit through which the disease reached the Mediterranean.

The Impact on Asian Societies

The demographic, economic, and political consequences of the plague in Asia are difficult to quantify with the precision available for Europe, where parish registers, tax records, and administrative documents provide a relatively detailed picture. Asian sources are generally less specific about mortality figures, and the political upheavals of the fourteenth century — the fall of the Yuan dynasty, the fragmentation of the Chagatai Khanate, the rise of Timur — make it difficult to isolate the effects of plague from those of warfare and political instability.

What is clear is that the pandemic struck Asian societies that were already under stress. The Mongol conquests of the thirteenth century had caused massive population displacement and economic disruption across much of Asia. The fourteenth century brought additional challenges: climatic deterioration associated with the onset of the Little Ice Age, agricultural failures, and the political fragmentation of the Mongol Empire. Plague was one element in a broader crisis that reshaped the political and demographic landscape of Asia as thoroughly as it did that of Europe.