The Black Death was one of the deadliest pandemics in human history, striking medieval Europe between 1347 and 1351 and killing an estimated 25–50% of the population. Caused by the bacterium Yersinia pestis, this bubonic plague spread rapidly along trade routes and through crowded cities, overwhelming medical knowledge and social structures of the time. Its aftermath led to dramatic socio-economic shifts, including labor shortages, peasant revolts, and changes in land use. Understanding the Black Death reveals how a single disease reshaped demographics, beliefs, and power dynamics across the Middle Ages.
A detailed record was kept of the Black Death by Samuel Pepys that gives a detailed account of how the Black Death killed up to 50% of Europe’s population.
The dominant explanation for the Black Death is the plague theory, which attributes the outbreak to the Yersinia pestis plague spread by Rat Fleas!
What caused the Black death?
In the medieval period, nobody really knew what caused the Black death or how to stop and treat it, this led to panic amongst medieval people. Historians believed that the Black Death was caused by the dirt and squalor that people lived in which was easily spread in crowded highly populated areas.

The city of London was a particularly dirty and highly populated place, it is believed that rats thrived in these conditions and that the black death was spread by fleas that lived on the rats and carried the ‘plague’ and transferred the disease to humans when they were bitten.

Symptoms
The symptoms of the Black Death or great plague were particularly gruesome, within minutes of being bitten by a rat flea the victim would break out in ‘black blotches’ and large painful lumps would appear all over their bodies.

The victims would be in excruciating pain for days shaking and vomiting, and parts of their bodies such as their fingers and toes would turn black and completely fall off until they finally succumbed to the disease and died.

Spread of the Disease
The Black Death quickly spread through the towns, villages, and cities of medieval times, the bigger more populated areas suffered the most. People were even afraid to leave their homes for fear of catching the plague and they would rather starve to death than risk catching the Black death.
A red cross was painted on the doors of the dead to warn others not to enter their homes. People were told to ‘Bring out ye dead’. The cry of ‘bring out your dead’ could be heard across London and other towns and cities in medieval England.
The corpses of people who had died from the Black death were thrown onto carts and dumped at the edge of towns and cities.
Death Toll
The Black Death wiped out a huge number of people, in London alone, it was believed that one in five of the population had been killed by the plague, that was around 68,000 Londoners.
In Europe, it is estimated that around 50% of the European Population died!
Samuel Pepys Diaries
Samuel Pepys was an MP (member of parliament) in medieval times and also worked at the Navy as an administrator. Much of what we know about the Black Death ‘plague’ is thanks to the detailed records that he kept from 1660 to 1669 in which he made notes in his diary almost every single day.

Samuel Pepys’s diary details the spread of the plague and gives his account of how the Black death affected him personally. Samuel Pepys diary describes what he witnessed as he walked through the streets of London, such as the Red Crosses being painted on the doors. The people in the streets were full of sores, and the sad stories that he heard as he walked around the city.
Black Death Doctors
Although medieval people did not know at that time what caused the Black death, bizarrely doctors walked around the city wearing leather robes, gloves, and strange masks that resembled bird beaks stuffed with herbs.
They believe that dressing this way protected them from the plague, they certainly looked ridiculous but it is doubtful that this protected them from such a vicious disease as the Black death.

How did the Black death end?
It is believed that the Black death spread more rapidly during hot weather ‘ there was a very cold snap ‘and it is believed that this cold weather eventually killed off the rats and led to the end of the great plague. So it was the cold winter weather that finally killed off the rats and stopped the plague from spreading any further.
This allowed the disease to be contained and the medieval villages towns and cities to be cleaned up.
Black Death Fast Facts
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- One theory is that the ‘Black Death’ was spread by fleas that were carried by black rats.
- Victims of the ‘Great Plague’ usually died within days.
- The Black Death was a painful death, people’s fingers toes, and noses would turn black and fall off.
- Nobody knew what caused the Black death and there was no cure.
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- People would rather starve to death than leave their houses and risk catching the ‘Black Death.
- The Black Death killed around 68,000 people in London alone.
- Samuel Pepys kept a detailed diary of events during the bubonic plague.
- Samuel Pepys wrote in his diary every day for around nine years.
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- Red Crosses were painted on the doors of people who had died of the Black death.
- People were told to ‘bring out their dead’ during the great plague.
- Doctors wore bizarre masks filled with herbs that they thought protected them from the Black death.
- The nursery rhyme ‘ring ‘O’ roses’ is believed to be about the Black death.
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