First and most devastating outbreak of the plague in Europe, 1347 - 1351.
The plague is an infectious disease of rodents transmitted by the rat flea that can develop into a deadly epidemic for humans. It originates from China and Inner Asia and was unknown in Europe before the 14th century AD. It came to Europe in 1347 through an act of biological warfare, when an army of Inner Asian nomad warriors besieged a Genoese outpost in the Crimea and catapulted infected corpses into the town.
Within 4 years the disease, known as the Black Death, had spread through all of Europe. The mortality varied from region to region between one-eight and two-thirds of the population. In England alone more than 1,000 villages were abandoned and disappeared completely, and its population in 1400 was about half of what it had been a century before. It took Europe 200 years to recover to the population level of 1340.
More outbreaks of the plague occurred in 1361 - 1363, 1369 - 1371, 1374 - 1375, 1390 and 1400. Localized outbreaks occurred throughout the next centuries.
The decimation of the European population lead to a large reduction of cultivated land, and the shortage of labour led to a significant rise of wages for artisans in the towns and general betterment of living conditions for peasants. The ruling classes, who suffered from the lack of available labour, tried to protect their status through the setting of maximum allowable wages, which led to the Peasants' Revolt, the first great popular uprising in medieval England, in 1381.
One of the most masterful and moving descriptions of the plague in a European city of the 17th century was given by the Italian writer Alessandro Manzoni in his novel I Promessi Sposi (The Betrothed).