Black Death

The **Black Death (1346-1353)** was a pandemic in Europe and Asia during the 14th century. It was at its worst between 1347 and 1352.

This outbreak of disease killed between 25 million and 50 million people across Europe. This was between 30% and 60% of Europe's population at the time. This was the deadliest event in known human history.

At the time, 14th-century European writers called the pandemic the "Great Mortality". After later epidemics, it was named "the Black Death."

## Cause

Historians and scientists cannot be sure which disease caused the Black Death. However, most think that it was the bubonic plague. That is a bacterial infection caused by the _Yersinia pestis_ species of bacteria.

Not everybody agrees that plague caused the Black Death. Some scientists and historians think it was anthrax or a viral hemorrhagic fever.

### Incorrect theories about causes

The plague happened far before scientists discovered germs, and people at the time had no way of understanding infections. Instead, they blamed the Black Death on other things.

#### Humorism

At the time, doctors believed in Hippocrates's theory of humorism. According to this theory, the body consists of different fluids. If these "humors" are in harmony (balanced well), a person is healthy. When they are out of balance, disease results.

#### Miasma

This theory did not explain why disease spreads from one person to another. Most people thought that infection was caused by _miasma_ ("bad air")_._ The bad air could come from within the earth and cause the disease. To protect against the disease, people tried many non-medical techniques. These included opening only north-facing windows; not sleeping during the day; and not working too hard.

#### Astrology

In 1348, Philip VI of France asked the Faculty of Medicine of the University of Paris about what caused the Black Death. The Faculty concluded that bad conjunction of Jupiter, Saturn and Mars on 20 March 1345 had caused the pandemic. Since that answer was based on astrology, many people believed it, and it was translated into many languages.

#### Religion

Many people thought diseases were a punishment from God. Trying to please God, many participated in religious ceremonies (including Confession and Communion). They also asked for forgiveness and did penance.

### Blaming the Jews

Many people believed the Jews were causing the plague by poisoning wells. As a result, Jews were victims of pogroms and massacres throughout Europe.

According to a 2005 book:> _Panic emerged ... during the scourge of the Black Death in 1348, when widespread terror prompted a revival of the well poisoning charge. In areas where Jews appeared to die of the plague in fewer numbers than Christians, possibly because of better hygiene [possibly related to religious practices] and greater isolation, lower mortality rates provided evidence of Jewish guilt._

A 2021 study also noted:> _Carriers of recessive familial Mediterranean fever (FMF) mutations have natural immunity against Y. pestis. During the Black Death, Jews were blamed for the bubonic plague, perhaps because Jews carried FMF mutations and died at lower plague rates than Christians. Blaming minorities for epidemics echoes across history[.]_

## History

The Black Death may have begun in Central or East Asia. It first appeared in Crimea in 1347.

According to Encyclopedia Britannica:> _The plague that caused the Black Death originated [started] in China in the early to mid-1300s and spread along trade routes westward to the Mediterranean and northern Africa. It reached southern England in 1348 and northern Britain and Scandinavia by 1350._Fleas living on black rats probably carried the disease. These rats traveled on Genoan ships and brought the plague to port cities around the Mediterranean. From there, the disease spread across Europe.

Rats may also have traveled along trade routes like the Silk Road and brought infected fleas to European cities. When the fleas bit humans, they infected them with the plague by injecting a bit of _Y. pestis_ bacteria into the wound. Symptoms would start three to seven days later.

### Germ warfare

The Black Death may have first infected Europeans in 1347. That year, Mongol forces used the plague as a biological weapon. This was one of the earliest uses of germ warfare in history.

In Crimea, Mongol soldiers were fighting for control of Caffa (now Feodosiya, Ukraine). Caffa was an important port and international trading center for traders from Genoa. From the port at Caffa, they could bring goods to many other parts of Europe and Asia.

To take control of Caffa, Mongol forces began a siege. Records say that during the siege, the Mongols catapulted plague-infested bodies over the walls into the city. Their goal was to make the people inside sick and thus weaken them or encourage them to leave Caffa. The strategy worked: Genoans fled the siege in ships. Still, the Caffa refugees may have brought the plague back to Italy with them; from there, it spread across Europe and Asia. The pandemic had begun.

### Reappearance

Until the 1700s, the plague reappeared in Europe at least once every generation. Some of the smaller plagues were more intense and deadly than others. Later outbreaks include the Italian Plague of 1629–1631, the Great Plague of London (1665–1666), the Great Plague of Vienna (1679), the Great Plague of Marseille in 1720–1722, and the 1771 plague in Moscow. Records suggest the most harmful form of the plague disappeared from Europe in the 18th century.

There were twelve plague outbreaks in Australia between 1900 and 1925. According to the National Museum of Australia, in total 1,371 cases of plague were reported and 535 people died, mainly in Sydney. A Public Health Department was opened and did some leading-edge research. The Department confirmed that plague was transmitted from rat fleas to humans by the bacillus _Yersinia pestis_.

### The plague today

Plague sometimes occurs today. It is considered an animal disease and is found in all continents except Oceania.

#### Risk of plague

There is a risk of human plague if all of these things are true:

- There is plague bacteria
- There is an animal reservoir: an animal that has plague, but does not get sick or give it to humans (like rats during the Black Death)
- There is a vector: a way for the plague to infect humans (like infected fleas during the Black Death)
- Humans live close to these animals

#### Death rates

According to the Cleveland Clinic:> _Immediate treatment with antibiotics will help you survive the plague. With quick treatment, about 90% of people with all forms of plague survive. Without treatment, plague is nearly always fatal. With treatment, there’s a 5 to 15% mortality (death) rate for bubonic plague and around a 50% mortality rate for pneumonic and septicemic plague._

#### Common locations

Plague epidemics have happened in Africa, Asia, and South America. However, since the 1990s, most most cases of human plague happen in Africa. Plague is most common today in three countries:

- Democratic Republic of the Congo
- Madagascar
- Peru

In Madagascar, cases of bubonic plague are reported nearly every year, during the epidemic season (between September and April).

### Symptoms

There are three types of plague: bubonic, pneumonic, and septicemic. These had different symptoms, causes of death, and death rates. While the Black Death was mostly caused by bubonic plague, some victims may have had pneumonic plague, septicemic plague, or a combination. It is possible for a person to have all three types at once.

#### Bubonic plague

_See the main article: Bubonic plague_

In the bubonic type, the plague bacteria infect the _lymph nodes_.

This was the most common type of plague during the Black Death. It was 30-60% fatal during the Black Death (death rates varied in different areas).

It spread when fleas bit rats who were infected with plague bacteria. When they bit humans, the fleas would pass the bacteria on to them. Humans rarely spread bubonic plague to each other.

In humans, the bubonic plague causes fevers; severe flu-like symptoms; and buboes (swollen, painful lymph nodes). Buboes appeared as large, black-and-purple swellings filled with pus (usually in the groin, under the arms, on the thighs, and behind the ears). Death can occur from organ failure; sepsis; pneumonia; or other causes.

Bubonic plague can spread to the lungs (causing pneumonic plague) and/or to the blood (causing septicemic plague).

#### Pneumonic plague

In pneumonic plague, the plague bacteria infect the _lungs_. This type of plague was _always_ fatal during the Black Death.

It is the most virulent (dangerous) form of plague, and can kill a person within 24 hours.

Pneumonic plague is very contagious. (This means it spreads easily from person to person.) Infected respiratory droplets fly through the air when a person with plague coughs, sneezes, breathes, or talks. When another person breathes in those infected droplets, they get sick.

#### Septicemic plague

_See the main article: Septicemic plague_

When a person has septicemic plague, the plague bacteria infect the _blood_.

This blood infection causes various problems that are extremely dangerous. It causes sepsis, which can be quite deadly. A victim's blood can lose its ability to clot and start bleeding uncontrollably. They might bleed into their skin and organs, resulting in organ failure. They might cough up blood so severely that they choked or drowned.

This type was 30-60% fatal during the Black Death (death rates varied in different areas). It was less common than bubonic or pneumonic plague.

This type of plague has several possible causes:

- Bites from an infected flea
- Respiratory droplets
- Body fluids of an animal with plague gets into a human's body through a cut on their skin
- Untreated bubonic or pneumonic plague

### Treatments

Today, plague is treated with antibiotics. But because nobody during the Black Death understood what caused the plague, doctors had no effective treatments. Often, doctors simply told their patients to go to Confession so that their sins would be forgiven if they died.

Eventually, the pandemic caused doctors to change their ideas about how the human body worked. Just 200 years later, Girolamo Fracastoro discovered that diseases spread through infection.

## Impact

The Black Death had a major effect on Europe's population. At the time, there were 75 million and 200 million people across Eurasia. The Black Death killed around a third of these people. Some areas were affected more than others; in some places, up to half of the population died.

The pandemic changed Europe's social structure and decreased the power of the Roman Catholic Church. This resulted in widespread persecution of minorities like Jews, Muslims, foreigners, beggars, and lepers.

The uncertainty of daily survival influenced people to live for the moment, as illustrated by Giovanni Boccaccio in _The Decameron_ (1353).

## Media

The Black Death appears in some modern literature and media, used as a subject or a setting. For example, Edgar Allan Poe's short story _The Masque of the Red Death_ (1842) is set in an unnamed country during a fictional plague that shares many things in common with the Black Death.

Albert Camus's writings used that theme too. His novel _The Plague_ (1947) discussed an Algerian plague outbreak in and how people reacted to the epidemic.

## Related pages

- Great Plague of London
- _Yersinia pestis_
- Pandemic
- History of Europe

### Primary sources online

- Agnolo di Tura's account
- Gabriele de' Mussi's account
- Marchionne di Coppo di Stefano Buonaiuti's account
- A Petrarch account  and More quotes from Petrarch

### Secondary sources online

- _The History Guide_ "Satan Triumphant: The Black Death"
- Symptoms, causes, pictures of bubonic plague
- Overview of the black death
- BBC news story on controversy over Black Death origins
- Examination of "Ring around the Rosy"'s relationship to the plague
- Black Death Overview from BBC history
- Plague and Public Health in Renaissance Europe . Primary source documents and analyisis
- Secrets of the Dead . Mystery of the Black Death  PBS
- Pandemics in Eastern Europe