When Was The Black Plague? What to Expect When

The Black Plague, also known as the Black Death, reached Europe in 1347 and swept across the continent by 1350. This first and most deadly wave of bubonic plague killed an estimated one-third of Europe’s population. The disease did not end there, however. Major outbreaks continued for centuries, with significant epidemics in London in 1665 and a modern pandemic that began in China in the 1850s and spread worldwide.

When Was The Black Plague Exactly?

The most famous outbreak of the Black Plague occurred between 1347 and 1351. Historians often call this the “Great Mortality” or the “Black Death” specifically. It arrived in Europe through trading ships that docked in Sicily, Italy, in October 1347. From there it moved north through Italy, France, Spain, and England, then into Germany, Scandinavia, and Russia.

The plague did not stop after 1351. It became endemic in Europe, meaning it kept returning in waves for the next 300 years. The Great Plague of London in 1665 was the last major outbreak in England. The plague never fully disappeared from the world, but it no longer caused the same catastrophic mortality after the 17th century.

What Caused the Black Plague?

The Black Plague is caused by the bacterium Yersinia pestis. This bacterium lives naturally in rodents, particularly rats and ground squirrels. Fleas carry the bacteria from infected rodents to humans. When a flea bites an infected rat and then bites a human, it can pass the bacteria directly into the human bloodstream.

Modern genetic testing of skeletons from medieval plague pits has confirmed that Yersinia pestis was the cause. This was not clear for centuries. Many earlier theories suggested the plague was caused by bad air, planetary alignment, or other mysterious forces. The bacterium was only identified in 1894 during a plague outbreak in Hong Kong.

The disease spreads in two main ways. The most common is through flea bites. The second way is through respiratory droplets when an infected person has pneumonic plague, which affects the lungs. This form spreads directly from person to person through coughing and sneezing.

How Did the Plague Affect the Human Body?

The symptoms appeared suddenly, usually 2 to 6 days after exposure to the bacteria. The most famous symptom was the bubo — a painful, swollen lymph node. Buboes typically appeared in the groin, armpit, or neck. These swellings could reach the size of an egg or even an apple.

Along with buboes, infected people developed high fever, chills, severe headache, and extreme weakness. Many experienced vomiting, muscle pain, and confusion. Without treatment, the bacteria spread through the bloodstream and caused sepsis. Some people developed dark patches on their skin from bleeding under the surface, which is where the name “Black Death” likely comes from.

The disease took three clinical forms:

• Bubonic plague — the most common form, spread by flea bites, with swollen lymph nodes as the key symptom.
• Septicemic plague — the bacteria enter the bloodstream directly, causing tissue death in fingers, toes, and the nose. This form can be fatal within hours.
• Pneumonic plague — the bacteria infect the lungs, causing coughing, chest pain, and bloody sputum. This is the only form that spreads directly between humans.

In the 14th century, the mortality rate for untreated bubonic plague was between 30% and 60%. Pneumonic and septicemic plague were almost always fatal without treatment.

How Was the Black Plague Treated Historically?

Medieval medicine had no effective treatment for the plague. Physicians used bloodletting, which made patients weaker. They applied poultices made of herbs, onions, or dried toad to the buboes to try to draw out the infection. None of these methods worked.

Some preventive measures were more useful, even if people did not understand why. Quarantine was one of them. Venice required ships to wait 40 days before docking — the word “quarantine” comes from the Italian quaranta giorni, meaning 40 days. This practice did reduce the spread of disease, even though it was based on tradition rather than germ theory.

Doctors wore distinctive protective clothing in the 17th century. The “plague doctor” outfit included a long coat, gloves, and a beak-shaped mask filled with herbs and spices. People believed the herbs would purify the air. The outfit probably offered some physical barrier against fleas, but the herbs themselves did nothing.

Is the Black Plague Still a Threat Today?

The plague still exists today, but it is treatable and relatively rare. The World Health Organization reports several hundred cases worldwide each year. Most occur in rural areas of Africa, Asia, and the Americas. In the United States, an average of about 7 human cases are reported annually, mostly in the southwestern states such as New Mexico, Arizona, and Colorado.

Modern antibiotics are highly effective against Yersinia pestis. Streptomycin, gentamicin, and doxycycline are the standard treatments. When diagnosed early, the mortality rate drops dramatically to about 10% or less. The key is prompt diagnosis and treatment.

Public health measures are also far more advanced. Surveillance of rodent populations, flea control, and prompt reporting of human cases prevent large outbreaks. The plague no longer poses the existential threat it did in the 14th century, but it has not been eradicated.

How Did the Black Plague Change Society?

The Black Plague reshaped Europe in ways that still influence the modern world. The massive population loss — roughly 25 million deaths in Europe alone — created severe labor shortages. Peasants and workers gained bargaining power because their labor was suddenly in high demand. This weakened the feudal system and contributed to the rise of a middle class.

The plague also changed medicine. Physicians began to question traditional authorities like Galen and Aristotle, whose theories had dominated for centuries. The failure of conventional medicine during the plague pushed doctors to observe patients more carefully and rely on direct evidence rather than ancient texts. This shift toward empirical observation laid groundwork for the scientific revolution.

Religious and cultural life changed too. Some people turned to extreme piety, while others abandoned restraint and pursued pleasure. Persecution of minority groups, particularly Jewish communities, increased as people searched for someone to blame. The plague also influenced art and literature, with themes of death and mortality becoming common subjects.

What Is the Difference Between the Black Plague and Other Plagues?

The term “plague” is used broadly today to mean any widespread, deadly epidemic. But the Black Plague specifically refers to the disease caused by Yersinia pestis. Other historical pandemics caused by the same bacterium include the Plague of Justinian in the 6th century and the modern pandemic that started in China in the 1850s.

The Plague of Justinian struck the Byzantine Empire in 541 AD and killed an estimated 25 to 50 million people over two centuries. The modern pandemic, which began in Yunnan, China, in 1855, spread to every inhabited continent and killed millions before antibiotics became available in the 1940s. All three pandemics were caused by the same bacterium, but they occurred in different historical contexts with different social and economic consequences.

Other famous epidemics — like smallpox, cholera, or the 1918 influenza — are often called plagues in casual language, but they are completely different diseases with different causes and treatments. The Black Plague is a specific disease with a specific cause, not a general term for any epidemic.