Black Death

The Black Death was a plague pandemic that occurred in Europe from 1346 to 1353. It was one of the most fatal pandemics in human history. It led to the deaths of up to 50 million people, around 30% to 60% of the European population and approximately 33% of the Middle Eastern population.

The disease was caused by the bacterium Yersinia pestis. It is primarily spread by flea bites, though it may also spread through contact with infected tissues or fluids and, in pneumonic cases, through respiratory droplets.

The Black Death had far-reaching effects on populations, economies, and culture. It has been tentatively considered the second plague pandemic, even though each of these outbreaks was separated by around 500 to 600 years.

The Black Death was the second great natural disaster to strike Europe during the late Middle Ages. The first was the Great Famine of 1315–1317. There were further outbreaks throughout the Late Middle Ages. Because of the crisis of the late Middle Ages, the European population did not return to its 14th-century level until the 16th century. Outbreaks of the plague kept recurring around the world until the early 19th century.

If you want to learn about other uses of the names "The Plague" and "Black Death," see The Plague (disambiguation) and Black Death (disambiguation).

Names

European writers at the time described the disease in Latin as pestis or pestilentia ('pestilence'), epidemia ('epidemic'), and mortalitas ('mortality'). Before the 1700s, English speakers called it the "pestilence", the "great pestilence", "the plague", or "the great death". Later, "the furste moreyn" (first murrain) or "first pestilence" was used to tell this event apart from other diseases and epidemics of plague. The 1347 plague was not called "black" in any European language at the time. The words "black death" had sometimes been used for other deadly diseases. In English, this plague was not called "Black death" until the 1750s, when the term first appeared in 1755 as a translation of Danish den sorte død, lit. 'the black death'. Swedish and Danish chroniclers made "black death" a name for the pandemic in the 15th and early 16th centuries, and in the 16th and 17th centuries other languages copied it as a calque: Icelandic svarti dauði, German der schwarze Tod, and French la mort noire. Before this, most European languages called it a version of the Latin magna mortalitas, lit. 'Great Death'.

The idea of Death being black is very old. Homer used it in the Odyssey to describe the monster Scylla, whose mouths were "full of black Death" (in Ancient Greek: πλεῖοι μέλανος Θανάτοιο, romanized: pleîoi mélanos Thanátoio). Seneca the Younger may have been the first to call an epidemic "black death" (mors atra), but only to describe how deadly and dark the disease's prognosis was. The French physician Gilles de Corbeil had used atra mors for a "pestilential fever" earlier. In 1350, the Belgian astronomer Simon de Covino used mors nigra in a poem linking the plague to a conjunction of Jupiter and Saturn, though this does not clearly connect to the 1347 pandemic. In 1823, the historian Elizabeth Penrose, writing as "Mrs Markham", called the 14th-century outbreak the "black death". In 1908, Cardinal Francis Aidan Gasquet noted that the name atra mors first appeared in a 1631 book on Danish history by J. I. Pontanus.

Previous plague epidemics

Main articles: Plague (disease) and First plague pandemic

Research from 2017 suggests that plague first infected people in Europe and Asia between the Late Neolithic and the Early Bronze Age. In 2018, researchers found evidence of Yersinia pestis in an ancient Swedish tomb. This may have been linked to the "Neolithic decline" around 3000 BCE, when European populations fell significantly. This early form of Y. pestis may have been different from more modern types. The first known signs of bubonic plague, which can spread through fleas, come from Bronze Age remains near Samara.

The symptoms of bubonic plague are first described in a fragment of Rufus of Ephesus, preserved by Oribasius. Ancient doctors suggest that bubonic plague had reached the Roman Empire before the reign of Trajan, six centuries before it arrived at Pelusium during the reign of Justinian I. In 2013, researchers confirmed that the cause of the plague of Justinian (541–549, with recurrences until 750) was Y. pestis. This outbreak is known as the first plague pandemic. In 610, the Chinese physician Chao Yuanfang described a "malignant bubo" that came on suddenly with high fever. The Chinese physician Sun Simiao, who died in 652, also wrote about a "malignant bubo" and plague that was common in Lingnan (Guangzhou).

Origin

The origin of the Black Death is disputed. Genetic studies suggest Yersinia pestis bacteria evolved about 7,000 years ago, at the start of the Neolithic, and strains spread by fleas appeared around 3,800 years ago in the late Bronze Age. It is still unclear exactly where the Black Death began, though some evidence points to China, Central Asia, West Asia, and Europe. The pandemic was reportedly first brought to Europe during the siege of the Genoese trading port of Caffa in Crimea by the Golden Horde army of Jani Beg in 1347. From Crimea, fleas living on black rats most likely carried the disease on Genoese ships. It spread through the Mediterranean Basin and reached North Africa, West Asia, and the rest of Europe via Constantinople, Sicily, and the Italian Peninsula. Evidence suggests that once it reached land, the Black Death mainly spread from person to person as pneumonic plague. This explains why it spread inland so quickly, faster than would be expected if the main vector had been rat fleas causing bubonic plague.

A 2026 study published in Nature found the oldest known evidence of plague outbreaks in human remains. Researchers found traces of Yersinia pestis DNA in the teeth of 18 ancient hunter-gatherers from four cemeteries near Lake Baikal in Siberia. The earliest cases date to about 5,500 years ago, roughly 200 years earlier than previously thought. The researchers concluded that the disease likely first spread from marmots through contact with raw organs or infected hides, and that it also passed between people through breathing. Many victims were young children, including three young girls buried side by side. Scientists have also searched for "patient zero," the earliest known victims. In 2022, researchers pointed to early victims at two cemeteries in the Chüy Valley near Lake Issyk-Kul in modern Kyrgyzstan. Gravestones there, written in Syriac, gave names, years of death, and often causes of death, showing a rise in deaths from "pestilence" in 1338–1339. DNA from the teeth of seven people at the cemeteries of Kara-Djigach and Burana showed Yersinia pestis. This confirms that the strain found in Kyrgyzstan came before the Black Death strains that devastated Europe and the Middle East starting in 1346–1347, and was their direct ancestor.

Causes

Main article: Theories of the Black Death

Early on, a report by the Medical Faculty of Paris said that a group of planets had caused "a great pestilence in the air," an idea known as miasma theory. Some Muslim doctors warned against trying to prevent or treat a disease sent by God, while others used the preventive steps and treatments for plague that Europeans also used. These doctors also relied on the writings of the ancient Greeks. Today, scientists think the main carrier is the Oriental rat flea (Xenopsylla cheopis), a species of flea that is the main vector for spreading Yersinia pestis, the germ behind most plague outbreaks. Both male and female fleas feed on blood and can pass on the infection. The germ is a bacterium that forms a biofilm that blocks the flea's gut, so when the flea feeds, the germs are pushed into the bite. Because of climate change in Asia, rodents left dried-out grasslands for more crowded areas, which spread the disease. Plague is enzootic, meaning it is commonly present in fleas carried by ground rodents, including marmots, in Central Asia, Kurdistan, West Asia, North India, Uganda, and the western United States. Alexandre Yersin, a pupil of Louis Pasteur, discovered Y. pestis during an epidemic of bubonic plague in Hong Kong in 1894, and he suggested the rat was the main way the disease spread. In 1898, Paul-Louis Simond found that fleas whose midguts were blocked by growing germs spread the infection by biting. The blocked fleas starved, bit more aggressively, and tried to clear the blockage through regurgitation, which pushed many germs into the host. When one population of rodents, which resisted the disease and acted as hosts, kept it endemic, and a second population without resistance died off, fleas moved on to other hosts, including people, starting a human epidemic.

Stronger proof came in 2010, when Haensch et al. published a study in PLOS Pathogens. Using polymerase chain reaction (PCR) methods, they found DNA and RNA of Y. pestis in tooth sockets from skeletons in mass graves across northern, central, and southern Europe linked to the Black Death. They concluded that Y. pestis was the causative agent of the plague that devastated Europe. In 2011, genetic evidence from victims buried at East Smithfield in England confirmed this, and Bos et al. published the first draft genome in Nature, which showed the strain was ancestral to most modern strains. Later studies placed this strain as an ancestor of the third plague pandemic and a descendant of the strain behind the Plague of Justinian, and DNA from 14th-century London skeletons was almost identical to a strain that hit Madagascar in 2013. Other evidence traced the source to the Tian Shan mountains in Kyrgyzstan.

Researchers face gaps in reliable records, since no Domesday Book-era census was taken in England before the poll tax of 1377, and plague victim numbers are often extrapolated from clergy figures. Some mathematical modelling of spread and transmission in 2018 suggested the human flea and body lice may have been the main carriers. Lars Walløe and Monica Green have argued that other, non-commensal animals may also have been involved, and archaeologist Barney Sloane argued that spread was person to person. Academic debate continues, but no single alternative explanation has gained wide acceptance. Many scholars suggest that plague mixed with other diseases, including typhus, smallpox, and respiratory infections, and that septicemic and pneumonic forms extended outbreaks across seasons. In 2014, Public Health England reported on 25 bodies exhumed in Clerkenwell, London, which supported the pneumonic idea. Osteoarcheologists have confirmed Y. pestis in burial sites across northern Europe through bones and dental pulp, though no other epidemic germ has been found to support the alternative explanations.

Transmission

A team of medical geneticists led by Mark Achtman said that Yersinia pestis "evolved in or near China" over 2,600 years ago. Later research led by Galina Eroshenko placed its origins in the Tian Shan mountains, on the border between Kyrgyzstan and China. Newer research found strains in the Caucasus region, which was once thought to exist only in China, so China's role is still debated. Graves of Nestorian people near Issyk-Kul, dating from 1338 to 1339, have inscriptions that mention plague, and some epidemiologists think they mark the start of the epidemic. Before the Black Death reached Constantinople in 1347, epidemics killed an estimated 25 million people across Asia. Some thought the disease travelled along the Silk Road, but Achtman argued it probably was not carried that way, since traders found it hard to use the road by 1325 and impossible by 1340. Records from travellers east of the Black Sea before the Crimean outbreak in 1346 do not describe its symptoms. Others suggested it may have spread with Mongol armies and traders, or by ship, and that rats on Zheng He's ships in the 15th century may have carried plague to Southeast Asia, India, and Africa. Research on the Delhi Sultanate and the Yuan dynasty found no clear sign of the Black Death in those regions. Ole Benedictow argued that it most likely started near Kaffa, on the northwestern shore of the Caspian Sea. Monica Green suggested that other parts of Eurasia lack the same evidence because four strains of Yersinia pestis became dominant in different places.

Plague was first brought to Europe by Genoese traders from their port of Kaffa in the Crimea in 1347. During a protracted siege of the city in 1345–1346, the Mongol Golden Horde army of Jani Beg, whose mainly Tatar troops were suffering from the disease, catapulted infected corpses over the walls. Genoese traders fled across the Black Sea to Constantinople, where the disease arrived in summer 1347. It killed the 13-year-old son of the Byzantine emperor, John VI Kantakouzenos, who wrote about it in a way modelled on Thucydides's account of the Plague of Athens. Nicephorus Gregoras, writing to Demetrios Kydones, described the rising death toll. Carried by ships, plague reached Sicily in October 1347, then Pisa, which was the entry point into northern Italy, and Marseilles. From Italy, the disease spread northwest, striking France, Spain, Portugal, and England by June 1348, then through Germany, Scotland, and Scandinavia. It was introduced into Norway in 1349 when a ship landed at Askøy, then spread to Bjørgvin, modern Bergen. It spread to northern Russia in 1352 and reached Moscow in 1353. Plague was less common in areas with weaker trade links, such as much of the Basque Country, parts of Belgium and the Netherlands, and isolated Alpine villages. In West Asia and North Africa, the pandemic caused serious losses of people and lasting changes to economic and social life. By autumn 1347 plague had reached Alexandria, and by late summer 1348 it reached Cairo, capital of the Mamluk Sultanate, a cultural centre of the Islamic world and the largest city in the Mediterranean Basin. The Bahriyya child sultan an-Nasir Hasan fled, and more than a third of the 600,000 residents died. Plague returned to Cairo more than fifty times over the next one and a half centuries. The disease also spread to Gaza, Damascus, and Aleppo, and to cities in the territory of modern Lebanon, Syria, Israel, and Palestine, including Ascalon, Acre, Jerusalem, Sidon, and Homs. In 1348–1349 it reached Antioch. In April 1348 Tunis was infected by ship from Sicily, and the epidemic in Morocco may have started from Almería in al-Andalus. Mecca became infected in 1348 by pilgrims performing the Hajj. In 1351 or 1352, the Rasulid sultan of Yemen, al-Mujahid Ali, carried plague home after his release from Mamluk captivity in Egypt. In 1349, Mosul suffered a massive epidemic, and Baghdad experienced a second round of the disease.

Symptoms of the plague include a fever of 38–41 °C (100–106 °F), headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise. Left untreated, 80% of victims die within eight days. The most common sign was buboes (or gavocciolos), which were swollen lumps in the groin, neck and armpits that oozed pus and bled when opened. Boccaccio wrote that these lumps could grow as large as an apple or an egg. Later, dark spots appeared on the arm, thigh or other parts of the body, and people with these spots were expected to die soon. Acute fever and vomiting of blood often followed, and most people died two to seven days after they were first infected.

Freckle-like spots and rashes, which may have been caused by flea-bites, were another possible sign. Lodewijk Heyligen, whose master Cardinal Giovanni Colonna died of plague in 1348, described a form called pneumonic plague, which infected the lungs. Its symptoms include fever, cough and blood-tinged sputum, and it has a mortality rate of 90–95%. Septicemic plague is the least common form, and without treatment it is almost always fatal. Its symptoms are high fevers and purple skin patches (purpura due to disseminated intravascular coagulation). In the pneumonic and septicemic forms, the disease moved so quickly that the swollen lymph nodes seen as buboes often had no time to develop.

Consequences

Main article: Consequences of the Black Death

Deaths

No one knows the exact number of deaths, and the death rate changed a lot from place to place. Some estimates say the plague may have killed between 75,000,000 and 200,000,000 people in Eurasia. A 2022 study of pollen samples from across Europe, from 1250 to 1450, found that the plague hit some areas very hard, such as Scandinavia, France, western Germany, Greece, and central Italy. Other areas, including central and eastern Europe, Iberia, and Ireland, kept growing their farm output.

Estimates suggest the Black Death killed from 25 to 60% of Europe's population. In 1351, agents for Pope Clement VI counted 23,840,000 dead in Christian Europe, according to historian Robert Gottfried. Historian Ole J. Benedictow proposed a death rate of 60% for Europe as a whole. Medieval historian Philip Daileader thought that over four years, 45–50% of Europe's population died.

Many deaths made mass burials necessary, and some sites held hundreds or thousands of bodies. In 1348, the disease spread so fast that nearly a third of Europe's population died before doctors or leaders understood where it came from. Half of the 100,000 people in Paris died. In Italy, the population of Florence fell from between 110,000 and 120,000 in 1338 to 50,000 in 1351. At least 60% of the people of Hamburg and Bremen died. Some areas were spared, and plague did not reach Flanders until the turn of the 15th century. Monks, nuns, and priests were especially hard hit because they cared for the sick.

In 1382, the physician to the Avignon Papacy, Raimundo Chalmel de Vinario, wrote about the plague in his book On Epidemics. He noticed that each outbreak from 1347 to 1382 caused fewer deaths than the one before. By the 1380s, the plague mostly affected children. Italian chronicler Agnolo di Tura, who lived in Siena, wrote about the terrible burials there. The Black Death also killed about 40% of Egypt's population.

Economic

The Black Death, like other outbreaks in history, seems to have hit the poorest people hardest, especially those already in poor health. After so many people died, wages rose because there were fewer workers. Some rents fell sharply. However, many workers and craftsmen lost buying power because prices rose quickly. The Mongol Empire also suffered trade problems caused by the disease, which was one reason for its collapse.

Environmental

A study by Thomas Van Hoof of Utrecht University suggests that the many deaths cooled the climate. Abandoned farmland was taken over by reforestation, which may have helped lead to the Little Ice Age.

Persecutions

See also: Persecution of Jews during the Black Death

Religious fanaticism grew after the Black Death. Some Europeans blamed groups such as Jews, friars, foreigners, beggars, pilgrims, and Romani for the crisis. People with lepers or skin diseases such as acne or psoriasis were also harmed. Many people believed the disease came from astrological forces, earthquakes, or the poisoning of wells by Jews. Many also thought it was a punishment by God for sins, which could be eased by winning God's forgiveness.

Many Jewish communities were attacked. In the Strasbourg massacre of February 1349, about 2,000 Jews were murdered. In August 1349, the Jewish communities in Mainz and Cologne were destroyed. By 1351, 60 major and 150 smaller Jewish communities had been destroyed. Many Jews moved to Poland, where King Casimir the Great welcomed them.

Social

See also: Black Death in medieval culture

Some thinkers believe the devastation in Florence changed how people in Italy saw the world, which may have helped lead to the Renaissance. Familiarity with death may have made people think more about life on Earth, rather than spirituality and the afterlife. Others argue that the plague sparked a new wave of piety, shown in the sponsorship of religious art. The Renaissance's rise also came from other factors, including an influx of Greek scholars after the fall of the Byzantine Empire.

Because so many people died, the value of workers rose, and ordinary people gained more freedom. Survivors often inherited property, and this may have weakened feudalism, which relied on fiefs. The word "quarantine" comes from this period. In 1377, the city-state of Ragusa (now Dubrovnik, Croatia) required new arrivals from plague areas to stay isolated for thirty days. This was later extended to forty days.

Many church institutions were also affected. Smaller monasteries and convents closed, and up to half of parish churches lost their priests. Cardinal Francis Aidan Gasquet wrote that the plague left the English Church in a state of crisis. He said that people first fell into despair, but later religious feeling returned in a new, more personal form, which helped lead to the growth of guilds.

Recurrences

Main article: Second plague pandemic

The plague returned again and again to Europe and the Mediterranean from the 14th to the 17th centuries. Historian Jean-Noël Biraben estimated that the plague was present somewhere in Europe every year from 1346 to 1671, though some researchers have cautioned against using his data without question. According to historian Geoffrey Parker, at least two million people in Spain's neighbour France died from the disease between 1600 and 1670. The plague also struck much of the Islamic world. Algiers lost 30,000 to 50,000 people in several outbreaks, and Baghdad sometimes lost two-thirds of its population. Plague remained a major event in Ottoman society until the 1800s.

Main article: Third plague pandemic

The third plague pandemic (1855–1960) started in China in the mid-19th century and spread to all inhabited continents, killing 10 million people in India alone. Scientists who visited Hong Kong in 1894 began studying the cause of the plague, and the French-Swiss bacteriologist Alexandre Yersin later gave his name to the bacterium. In the United States, the first major plague epidemic was the San Francisco plague of 1900–1904. Today, treatments include insecticides, antibiotics, and a plague vaccine. Scientists fear the plague bacterium could develop drug resistance and again become a major health threat. A drug-resistant form was found in Madagascar in 1995, and in October 2017 the deadliest outbreak of the plague in modern times hit Madagascar, killing 170 people. After the introduction of antibiotics, the case fatality rate for the modern plague is estimated at 11%, although it may be higher in poorer regions.