The Black Death, also known as the Great Plague or the Plague, or less commonly the Black Plague, was one of the most devastating pandemics in human history, resulting in the deaths of an estimated 75 to 200 million people in Eurasia and peaking in Europe from 1347 to 1351.The bacterium Yersinia pestis, which results in several forms of plague, is believed to have been the cause.The Black Death was the first major European outbreak of plague, and the second plague pandemic.The plague created a number of religious, social and economic upheavals which had profound effects on the course of European history.
The Black Death is thought to have originated in the dry plains of Central Asia, where it travelled along the Silk Road, reaching Crimea by 1343.From there, it was most likely carried by fleas living on the black rats that travelled on all merchant ships, spreading throughout the Mediterranean Basin and Europe.
The Black Death is estimated to have killed 30% to 60% of Europe’s population.In total, the plague may have reduced the world population from an estimated 450 million to 350–375 million in the 14th century. It took 200 years for the world population to recover to its previous level. The plague recurred as outbreaks in Europe until the 19th century.
The plague disease, caused by Yersinia pestis, is enzootic (commonly present) in populations of fleas carried by ground rodents, including marmots, in various areas including Central Asia, Kurdistan, Western Asia, North India and Uganda.Due to climate change in Asia, rodents began to flee the dried out grasslands to more populated areas, spreading the disease. Nestorian graves dating to 1338–1339 near Issyk-Kul in Kyrgyzstan have inscriptions referring to plague and are thought by many epidemiologists to mark the outbreak of the epidemic, from which it could easily have spread to China and India. In October 2010, medical geneticists suggested that all three of the great waves of the plague originated in China.
The 13th-century Mongol conquest of China caused a decline in farming and trading. However, economic recovery had been observed at the beginning of the fourteenth century. In the 1330s, a large number of natural disasters and plagues led to widespread famine, starting in 1331, with a deadly plague arriving soon after. Epidemics that may have included plague killed an estimated 25 million Chinese and other Asians during the fifteen years before it reached Constantinople in 1347.
The disease may have travelled along the Silk Road with Mongol armies and traders or it could have come via ship. By the end of 1346, reports of plague had reached the seaports of Europe: “India was depopulated, Tartary, Mesopotamia, Syria, Armenia were covered with dead bodies”.
Plague was reportedly first introduced to Europe via Genoese traders from the port city of Kaffa in the Crimea in 1347. During a protracted siege of the city by the Mongol army under Jani Beg, whose army was suffering from the disease, the army catapulted infected corpses over the city walls of Kaffa to infect the inhabitants. The Genoese traders fled, taking the plague by ship into Sicily and the south of Europe, whence it spread north. Whether or not this hypothesis is accurate, it is clear that several existing conditions such as war, famine, and weather contributed to the severity of the Black Death.
An estimate of the mortality rate for the modern bubonic plague, following the introduction of antibiotics, is 11%, although it may be higher in underdeveloped regions.Symptoms of the disease include fever of 38–41 °C (100–106 °F), headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise. Left untreated, of those that contract the bubonic plague, 80 percent die within eight days. Pneumonic plague has a mortality rate of 90 to 95 percent. Symptoms include fever, cough, and blood-tinged sputum. As the disease progresses, sputum becomes free-flowing and bright red. Septicemic plague is the least common of the three forms, with a mortality rate near 100%. Symptoms are high fevers and purple skin patches (purpura due to disseminated intravascular coagulation). In cases of pneumonic and particularly septicemic plague, the progress of the disease is so rapid that there would often be no time for the development of the enlarged lymph nodes that were noted as buboes.
There are no exact figures for the death toll; the rate varied widely by locality. In urban centres, the greater the population before the outbreak, the longer the duration of the period of abnormal mortality. It killed some 75 to 200 million people in Eurasia.