The second plague pandemic was a major series of epidemics of plague that started with the Black Death, which reached medieval Europe in 1346 and killed up to half of the population of Eurasia in the next four years. It followed the first plague pandemic that began in the 6th century with the Plague of Justinian, but had ended in the 8th century. Although the plague died out in most places, it became endemic and recurred regularly. A series of major epidemics occurred in the late 17th century, and the disease recurred in some places until the late 18th century or the early 19th century. After this, a new strain of the bacterium gave rise to the third plague pandemic, which started in Asia around the mid-19th century.

The third plague pandemic was a major bubonic plague pandemic that began in Yunnan, China, in 1855. This episode of bubonic plague spread to all inhabited continents, and ultimately led to more than 12 million deaths in India and China, and at least 10 million Indians were killed in British Raj India alone, making it one of the deadliest pandemics in history. According to the World Health Organization, the pandemic was considered active until 1960 when worldwide casualties dropped to 200 per year. Plague deaths have continued at a lower level for every year since.