The Black Death, also known as the Black Plague, was a devastating pandemic that first struck Europe in the mid-late-14th century (13471351), killing between a third and two thirds of Europe's population. Almost simultaneous epidemics occurred across large portions of Asia and the Middle East during the same period, indicating that the European outbreak was actually part of a multi-regional pandemic. Including Middle Eastern lands, India and China, the Black Death killed at least 75 million people.

The Black Death had a drastic effect on Europe's population, irrevocably changing Europe's social structure. It was a serious blow to the Roman Catholic Church, Europe's predominant religious institution at the time, and resulted in widespread persecution of minorities such as Jews, Muslims, Slavs and lepers. The uncertainty of daily survival created a general mood of morbidity influencing people to live for the moment, as illustrated by Giovanni Boccaccio in The Decameron (1353).
The initial fourteenth-century European event was called the "Great Mortality" by contemporary writers and, with later outbreaks, became known as the "Black Death".[//citation needed//] It has been popularly thought that the name came from a striking symptom of the disease, called acral necrosis, in which sufferers' skin would blacken due to subdermal haemorrhages. However, the term refers in fact to the figurative sense of "black" (glum, lugubrious or dreadful).[1] Historical records have convinced most scientists that the Black Death was an outbreak of bubonic plague, caused by the bacterium Yersinia pestis and spread by fleas with the help of animals like the black rat (Rattus rattus), however, there are some scientists who question this.