The most virulent epidemic of bubonic and pneumonic plague ever recorded. It reached Europe from the Tartar armies, fresh from campaigning in the Crimea, who besieged the port of Caffa (1347). Rats carrying infected fleas swarmed aboard trading vessels, thus transmitting the plague to southern Europe. By 1348 it reached France, Spain, and England; a year later Germany, Russia, and Scandinavia. Numbers of dead cannot be exact but up to 25,000,000 may have died in Europe, including perhaps one-third of the population in England.
Black Death The Black Death was the most devastating of many outbreaks of plague. Although its origins are uncertain, it is believed to have come from the Far East and to have been carried westward to Europe by merchants, pilgrims, and other travellers. It spread especially fast along sea trade routes, transmitted by the fleas of rats on board ship. The particular virulence of this epidemic may have been due to the presence of the more deadly pneumonic variety of plague, the only form that can be directly transmitted from one human to another (by sneezing, for example). It is estimated that as much as one-third of the population of Europe and the Near East died as a result of this outbreak in less than 20 years.