black death black death the black death (also known as the pestilence, the great mortality or the plague) was a bubonic plague pandemic occurring in western eurasia and north africa from 1346 to 1353. it is the most fatal pandemic recorded in human history, causing the deaths of 75–200 million people, peaking in europe from 1347 to 1351. bubonic plague is caused by the bacterium yersinia pestis spread by fleas, but during the black death it probably also took a secondary form, spread by person-to-person contact via aerosols, causing pneumonic plague. black deaththe spread of the black death in europe, north africa and the near east (1346–1353) diseasebubonic plaguelocationeurasia and north africadate1346–1353deaths75,000,000–200,000,000 (estimated) the black death was the beginning of the second plague pandemic. the plague created religious, social and economic upheavals, with profound effects on the course of european history. the origin of the black death is disputed. genetic analysis points to the evolution of yersinia pestis in the tian shan mountains on the border between kyrgyzstan and china 2,600 years ago. the immediate territorial origins of the black death and its outbreak remains unclear with some pointing towards central asia, china, the middle east and europe. the pandemic was reportedly first introduced to europe during the siege of the genoese trading port of kaffa in crimea by the golden horde army of jani beg in 1347. from crimea, it was most likely carried by fleas living on the black rats that travelled on genoese ships, spreading through the mediterranean basin and reaching north africa, western asia and the rest of europe via constantinople, sicily and the italian peninsula. there is evidence that once it came ashore, the black death mainly spread person-to-person as pneumonic plague, thus explaining the quick inland spread of the epidemic, which was faster than would be expected if the primary vector was rat fleas causing bubonic plague. in 2022, it was discovered that there was a sudden surge of deaths in what is today kyrgyzstan from the black death in the late 1330s; when combined with genetic evidence, this implies that the initial spread may not have been due to mongol conquests in the 14th century, as previously speculated. the black death was the second great natural disaster to strike europe during the late middle ages (the first one being the great famine of 1315–1317) and is estimated to have killed 30 percent to 60 percent of the european population, as well as about one-third of the population of the middle east. the plague might have reduced the world population from c. 475 million to 350–375 million in the 14th century. there were further outbreaks throughout the late middle ages and, with other contributing factors (the crisis of the late middle ages), the european population did not regain its level in 1300 until 1500. outbreaks of the plague recurred around the world until the early 19th century. names european writers contemporary with the plague described the disease in latin as pestis or pestilentia, 'pestilence'; epidemia, 'epidemic'; mortalitas, 'mortality'. in english prior to the 18th century, the event was called the "pestilence" or "great pestilence", "the plague" or the "great death". subsequent to the pandemic "the furste moreyn" (first murrain) or "first pestilence" was applied, to distinguish the mid-14th century phenomenon from other infectious diseases and epidemics of plague. the 1347 pandemic plague was not referred to specifically as "black" in the time of occurrence in any european language, though the expression "black death" had occasionally been applied to fatal disease beforehand. "black death" was not used to describe the plague pandemic in english until the 1750s; the term is first attested in 1755, where it translated danish: den sorte død, lit. 'the black death'. this expression as a proper name for the pandemic had been popularized by swedish and danish chroniclers in the 15th and early 16th centuries, and in the 16th and 17th centuries was transferred to other languages as a calque: icelandic: svarti dauði, german: der schwarze tod, and french: la mort noire. previously, most european languages had named the pandemic a variant or calque of the latin: magna mortalitas, lit. 'great death'. the phrase 'black death' – describing death as black – is very old. homer used it in the odyssey to describe the monstrous scylla, with her mouths "full of black death" (ancient greek: πλεῖοι μέλανος θανάτοιο, romanized: pleîoi mélanos thanátoio). seneca the younger may have been the first to describe an epidemic as 'black death', (latin: mors atra) but only in reference to the acute lethality and dark prognosis of disease. the 12th–13th century french physician gilles de corbeil had already used atra mors to refer to a "pestilential fever" (febris pestilentialis) in his work on the signs and symptoms of diseases (de signis et symptomatibus aegritudium). the phrase mors nigra, 'black death', was used in 1350 by simon de covino (or couvin), a belgian astronomer, in his poem "on the judgement of the sun at a feast of saturn" (de judicio solis in convivio saturni), which attributes the plague to an astrological conjunction of jupiter and saturn. his use of the phrase is not connected unambiguously with the plague pandemic of 1347 and appears to refer to the fatal outcome of disease. the historian cardinal francis aidan gasquet wrote about the great pestilence in 1893 and suggested that it had been "some form of the ordinary eastern or bubonic plague". in 1908, gasquet said use of the name atra mors for the 14th-century epidemic first appeared in a 1631 book on danish history by j. i. pontanus: "commonly and from its effects, they called it the black death" (vulgo & ab effectu atram mortem vocitabant). previous plague epidemics yersinia pestis (200 × magnification), the bacterium that causes plague main articles: plague (disease) and first plague pandemic research from 2017 suggests plague first infected humans in europe and asia in the late neolithic-early bronze age. research in 2018 found evidence of yersinia pestis in an ancient swedish tomb, which may have been associated with the "neolithic decline" around 3000 bce, in which european populations fell significantly. this y. pestis may have been different from more modern types, with bubonic plague transmissible by fleas first known from bronze age remains near samara. the symptoms of bubonic plague are first attested in a fragment of rufus of ephesus preserved by oribasius; these ancient medical authorities suggest bubonic plague had appeared in the roman empire before the reign of trajan, six centuries before arriving at pelusium in the reign of justinian i. in 2013, researchers confirmed earlier speculation that the cause of the plague of justinian (541–542 ce, with recurrences until 750) was y. pestis. this is known as the first plague pandemic. in 610, the chinese physician chao yuanfang described a "malignant bubo" "coming in abruptly with high fever together with the appearance of a bundle of nodes beneath the tissue." the chinese physician sun simo who died in 652 also mentioned a "malignant bubo" and plague that was common in lingnan (guangzhou). ole jørgen benedictow believes that this indicates it was an offshoot of the first plague pandemic which made its way eastward to chinese territory by around 600. 14th-century plague early theory the most authoritative contemporary account is found in a report from the medical faculty in paris to philip vi of france. it blamed the heavens, in the form of a conjunction of three planets in 1345 that caused a "great pestilence in the air" (miasma theory). muslim religious scholars taught that the pandemic was a "martyrdom and mercy" from god, assuring the believer's place in paradise. for non-believers, it was a punishment. some muslim doctors cautioned against trying to prevent or treat a disease sent by god. others adopted preventive measures and treatments for plague used by europeans. these muslim doctors also depended on the writings of the ancient greeks. predominant modern theory the oriental rat flea (xenopsylla cheopis) engorged with blood. this species of flea is the primary vector for the transmission of yersinia pestis, the organism responsible for spreading bubonic plague in most plague epidemics. both male and female fleas feed on blood and can transmit the infection.oriental rat flea (xenopsylla cheopis) infected with the yersinia pestis bacterium which appears as a dark mass in the gut. the foregut (proventriculus) of this flea is blocked by a y. pestis biofilm; when the flea feeds on an uninfected host y. pestis is regurgitated into the wound, causing infection. due to climate change in asia, rodents began to flee the dried-out grasslands to more populated areas, spreading the disease. the plague disease, caused by the bacterium 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, uganda and the western united states. y. pestis was discovered by alexandre yersin, a pupil of louis pasteur, during an epidemic of bubonic plague in hong kong in 1894; yersin also proved this bacillus was present in rodents and suggested the rat was the main vehicle of transmission. the mechanism by which y. pestis is usually transmitted was established in 1898 by paul-louis simond and was found to involve the bites of fleas whose midguts had become obstructed by replicating y. pestis several days after feeding on an infected host. this blockage starves the fleas and drives them to aggressive feeding behaviour and attempts to clear the blockage by regurgitation, resulting in thousands of plague bacteria being flushed into the feeding site, infecting the host. the bubonic plague mechanism was also dependent on two populations of rodents: one resistant to the disease, which act as hosts, keeping the disease endemic, and a second that lacks resistance. when the second population dies, the fleas move on to other hosts, including people, thus creating a human epidemic. dna evidence skeletons in a mass grave from 1720 to 1721 in martigues, near marseille in southern france, yielded molecular evidence of the orientalis strain of yersinia pestis, the organism responsible for bubonic plague. the second pandemic of bubonic plague was active in europe from 1347, the beginning of the black death, until 1750. definitive confirmation of the role of y. pestis arrived in 2010 with a publication in plos pathogens by haensch et al. they assessed the presence of dna/rna with polymerase chain reaction (pcr) techniques for y. pestis from the tooth sockets in human skeletons from mass graves in northern, central and southern europe that were associated archaeologically with the black death and subsequent resurgences. the authors concluded that this new research, together with prior analyses from the south of france and germany, "ends the debate about the cause of the black death, and unambiguously demonstrates that y. pestis was the causative agent of the epidemic plague that devastated europe during the middle ages". in 2011, these results were further confirmed with genetic evidence derived from black death victims in the east smithfield burial site in england. schuenemann et al. concluded in 2011 "that the black death in medieval europe was caused by a variant of y. pestis that may no longer exist". later in 2011, bos et al. reported in nature the first draft genome of y. pestis from plague victims from the same east smithfield cemetery and indicated that the strain that caused the black death is ancestral to most modern strains of y. pestis. since this time, further genomic papers have further confirmed the phylogenetic placement of the y. pestis strain responsible for the black death as both the ancestor of later plague epidemics including the third plague pandemic and as the descendant of the strain responsible for the plague of justinian. in addition, plague genomes from significantly earlier in prehistory have been recovered. dna taken from 25 skeletons from 14th century london have shown plague is a strain of y. pestis almost identical to that which hit madagascar in 2013. further dna evidence also proves the role of y. pestis and traces the source to the tian shan mountains in kyrgyzstan. alternative explanations it is recognised that an epidemiological account of plague is as important as an identification of symptoms, but researchers are hampered by the lack of reliable statistics from this period. most work has been done on the spread