Medieval people called the 14th century catastrophe either the "Great Pestilence"' the "Great Death"' or the "Great Plague".^[14] Contemporary writers then referred to the event as the "Great Mortality"; the term "Black Death" was introduced for the first time in 1833. ^[15] It has been popularly thought that the name came from a striking late-stage sign of the disease, in which the sufferer's skin would blacken due to subepidermal hemorrhages (purpura), and the extremities would darken with gangrene (acral necrosis). However, the term most likely refers to the sense of "black" (glum, lugubrious or dreadful).^[16]

The Black Death was, according to historical accounts, characterized by buboes (swellings in lymph nodes), like the late 19th century Asian Bubonic plague. Scientists and historians at the beginning of the 20th century assumed that the Black Death was an outbreak of the same disease, caused by the bacterium Yersinia pestis and spread by fleas with the help of animals like the black rat. (Rattus rattus). However, this view has recently been questioned by scientists and historians.^[17][18]

The scenario that would place the first outbreak in central Asia agrees with the first reports of outbreaks in China in the early 1330s. The plague struck the Chinese province of Hubei in 1334. On the heels of the European epidemic, more widespread disaster occurred in China during 1353–1354. Chinese accounts of this wave of the disease record a spread to eight distinct areas: Hubei, Jiangxi, Shanxi, Hunan, Guangdong, Guangxi, Henan and Suiyuan,^[26] throughout the Mongol and Chinese empires. Historian William McNeill noted that voluminous Chinese records on disease and social disruption survive from this period, but no one has studied these sources in depth.

It is probable that the Mongols and merchant caravans inadvertently brought the plague from central Asia to the Middle East and Europe. The plague was reported in the trading cities of Constantinople and Trebizond in 1347. In that same year, the Genoese possession of Caffa, a great trade emporium on the Crimean peninsula, came under siege by an army of Mongol warriors under the command of Janibeg, backed by Venetian forces. After a protracted siege during which the Mongol army was reportedly withering from the disease, they might have decided to use the infected corpses as a biological weapon. The corpses were catapulted over the city walls, infecting the inhabitants.^[27] The Genoese traders fled, transferring the plague via their ships into the south of Europe, whence it rapidly spread. According to accounts, so many died in Caffa that the survivors had little time to bury them and bodies were stacked like cords of firewood against the city walls.

The plague struck various countries in the Middle East during the pandemic, leading to serious depopulation and permanent change in both economic and social structures. As it spread to western Europe, the disease also entered the region from southern Russia. By autumn 1347, the plague reached Alexandria in Egypt, probably through the port's trade with Constantinople, and ports on the Black Sea. During 1348, the disease travelled eastward to Gaza, and north along the eastern coast to cities in Lebanon, Syria and Palestine, including Ashkelon, Acre, Jerusalem, Sidon, Damascus, Homs, and Aleppo. In 1348–49, the disease reached Antioch. The city's residents fled to the north, most of them dying during the journey, but the infection had been spread to the people of Asia Minor.

Mecca became infected in 1349. During the same year, records show the city of Mawsil (Mosul) suffered a massive epidemic, and the city of Baghdad experienced a second round of the disease. In 1351, Yemen experienced an outbreak of the plague. This coincided with the return of King Mujahid of Yemen from imprisonment in Cairo. His party may have brought the disease with them from Egypt.

In England, in the absence of census figures, historians propose a range of pre-incident population figures from as high as 7 million to as low as 4 million in 1300, and a post-incident population figure as low as 2 million.^[28] By the end of 1350 the Black Death had subsided, but it never really died out in England over the next few hundred years: there were further outbreaks in 1361-62, 1369, 1379-83, 1389-93, and throughout the first half of the 15th century.^[29] Plague often killed 10% of a community in less than a year - in the worst epidemics, such as at Norwich in 1579 and Newcastle in 1636, as many as 30 or 40%. The most general outbreaks in Tudor and Stuart England, all coinciding with years of plague in Germany and the Low Countries, seem to have begun in 1498, 1535, 1543, 1563, 1589, 1603, 1625 and 1636.^[30]

The plague repeatedly returned to haunt Europe and the Mediterranean throughout the fourteenth to seventeenth centuries, and although bubonic plague still occurs in isolated cases today, the Great Plague of London in 1665–1666 is generally recognized as one of the last major outbreaks.^[31]

Late outbreaks in central Europe include the Italian Plague of 1629-1631, which is associated with troop movements during the Thirty Years' War, and the Great Plague of Vienna in 1679. About 200,000 people in Moscow died of the disease from 1654 to 1656.^[32] The last plague outbreak ravaged Oslo in 1654.^[33] In 1656 the plague killed about half of Naples's 300,000 inhabitants.^[34] Amsterdam was ravaged in 1663–1664, with a mortality given as 50,000.^[35]

A plague epidemic that followed the Great Northern War (1700-1721, Sweden v. Russia and allies) wiped out almost 1/3 of the population in the region.^[36] An estimated one-third of East Prussia's population died in the plague of 1709-1711.^[37] The plague of 1710 killed two-thirds of the inhabitants of Helsinki.^[38] An outbreak of plague between 1710 and 1711 claimed a third of the Stockholm’s population.^[39]