The Black Death tore through Western Europe in the mid-14th century CE, reducing the world’s entire population by roughly 100,000,000 people. Today we know that the Great Pestilence is caused by bacteria carried by fleas and rodents, but back in the time of Edward III and the Hundred Years’ War, there was little that the people of Europe and South Africa could do to stave off the disease.
But the onset of the disease showed people that it didn’t matter whether they were rich or poor, God was striking people down left and right, ushering in the end of the Catholic Church’s rule and the collapse of feudalism.
Here are 10 fascinating facts about the greatest pestilence in recorded history, the Black Death.
10. It is Extremely Virulent
After multiple plague outbreaks over centuries and deaths in the hundreds of millions, we still didn’t know what exactly caused these deadly outbreaks. It wasn’t until 1894 that a scientist by the name of Alexandre Yersinia discovered the bacterium responsible for the outbreaks, called Yersinia pestis. Yersinia pestis is extraordinarily aggressive, jumping from host to humans and disabling our immune systems by injecting toxins into our macrophages (the defense cells in our bodies which are meant to detect bacterial infections).
Yersinia pestis can host in a plethora of mammals such as rats, mice, prairie dogs, squirrels, and rabbits. For centuries, we believed that rats were the main hosts for the plague, but this simply isn’t true. The bacterium can host in low quantities in these mammals, during what’s called an enzootic cycle. It’s during this period that outbreaks are unlikely, but when an epizootic cycle starts, that’s when humans face the greatest risk of an outbreak.
While rats do carry the bacterium, and they do tend to favor our urban developments, they aren’t the main cause of the plague in humans. The flea species, Xenopsylla cheopis is the primary culprit. These nasty critters favor rats, but when their hosts die of the plague, they tend to jump ship (for lack of a better word), and who do you think ends up being their next meal? That’s right: Us. When these fleas bite humans, they spread the plague carried by their former host.
9. It Evolved in China
Modern gene sequencing has revealed that the Black Death may have originated from China, suggesting that it evolved there over 2,000 years ago.
After comparing 17 complete sequences of plague genomes in a decentralized collaboration with several countries, scientists were able to trace the history of the plague and map its spread in a way that is completely unprecedented. The reason for such a massive collaboration is because Yersinia pestis is a highly controlled bacterium, on the level of something like smallpox, so access to it is highly restricted. This is to prevent bioterrorism, but it also makes working with the bacterium much more difficult.
The authors of this new study (written in the journal Nature Genetics) say that the bacterium originally evolved in the area of China and spread globally multiple times, resulting in devastating pandemics. From here it spread to West Asia through the silk road, Africa between 1409-1433 thanks to Chinese travelers who unknowingly had the plague, and Europe and Africa again in 1346-1351 thanks to fleas and black rats stowing aboard trade ships.
The study notes that 50% of China’s population perished due to the outbreak of Yersinia pestis, Europe by a 1/3rd, and Africa by 1/8th.
8. It Caused an Economic Collapse During Edward III’s Rule
As the Black Death ravaged the population in Europe, the supply of peasants willing to work for a Lord laboring in their fields dwindled, and workers demanded higher wages as a result of the danger inherent in that work. Under the feudal system with which most of the world was ruled, peasants had virtually no rights to do as they pleased, having to ask permission before leaving their home city and being unable to let their daughters wed without their Lord’s permission. The Black Death showed people that God infected both the wealthy and the poor alike, creating new ideas like equality and self-respect in peasants, much to the chagrin of their rulers.
Edward III attempted to keep wages and prices from rising by passing the Statute of Labourers in 1351. The statute made it so that any healthy person under the age of 60 who did not work for a person that was willing to hire them would be fined and put in stocks as punishment (that wooden device you’ve probably seen in movies which features three round holes for the hands and head of a prisoner to be restrained, usually opening up in the middle with metal joints at one end of the device).
Statutes like this weren’t very effective, though, and wages would increase as feudalism slowly eroded (along with the Catholic church’s hold on society).
7. It Reduced the World’s Population by 100,000,000
In the 14th century, at least 75,000,000 people were killed by the Black Death in three different countries. Few regions were spared from “the Great Pestilence” and in European cities, people were dying by the hundreds daily. Those infected rarely lasted more than three days, sporting an astonishing 50-70% mortality rate. The pestilence was so bad, that bodies were piled on top of each other in mass graves. There simply weren’t enough people left untouched by the plague to bury the dead.
The world’s population would suffer so greatly, that it would not recover for several centuries.
6. It Slowed the Hundred Years’ War to a Crawl
Though Edward III’s thirst for conquest could not be abated for long, and the war would continue even as the Black Death ravaged Western Europe, the fighting would slow to a crawl. It is estimated that at least 25 million Europeans alone were killed by the disease, and this had grave consequences for the war effort going forward.
As the kingdom became saddled with debt thanks to expensive campaigns waged by Edward III, common knights took matters into their own hands, plundering their surrounding countryside. These groups would not admit to being bandits, and many of them were able to hold onto their authority, even as they instigated small-scale skirmishes and wars of their own.
5. Royalty Were Not Immune to Its Effects
Across Europe, the wealthy and the elite would fall. Edward III’s supporters and family were not immune to the effects of the disease, despite their ability to flee infected areas. The King’s favorite daughter, Joan, grew wary of the plague when a leader of her retinue died. She was moved to a nearby village to keep her isolated from infected individuals but ended up succumbing to the Black Death all the same in July of 1348.
The Church was also seriously affected by the Great Pestilence, and members of monastic temples were especially hard hit. King Edward III’s own physician would succumb to the Black Death, and his attendants and the Archbishop (appointed by the King himself) would follow.
4. Its Symptoms Are Devastating
Symptoms of the plague often included the development of a fever, headache, chills, and weakness 1 to 6 days after exposure to the bacteria. Swollen lymph nodes are also attributed to the early stages of the disease, surrounding the place where they were bitten (most likely by a flea carrying the plague), followed by swelling in the groin, armpits, and the neck, as well as dark patches that would appear on an infected person’s skin. This swelling is an extreme enlarging of the lymph nodes, caused by the disease. In modern cases, it has been noted that if left untreated, this swelling will spread to other parts of the body.
Those afflicted with the Black Death would often cough up blood and could live anywhere from half a day to five days before finally perishing from it.
3. People in the 14th Century Thought the Plague Came from God
Prior to the discovery that the Black Death was caused by bacteria carried by rodents and fleas, the people in Western Europe who were most affected by the plague had all sorts of strange theories for how to cure it.
Most people back then believed the disease was caused by divine judgment and thought that prayer was the only true cure, but others attributed the onset of plague to the devil, and even the alignment of the planets. People also believed that “bad air” or misaligned “humors” in the body could lead to the Black Death as well.
Ineffectual “cures” ranged from animal parts, potions, fumigations, bloodletting, and pastes. People also believed that leaving an infected area to be a good means of warding off the disease. Sadly, many Europeans also blamed the Jews for the outbreak, and they suffered greatly for this falsehood.
Surprisingly, though, there were groups of people who thought that quarantine and social distancing would also stave off the disease.
2. The Worst Hit Areas were Mountainous and Isolated Places
Despite being transmitted along trade routes (primarily by sea) the hardest hit zones in Western Europe were in mountainous or isolated areas. Snowdonia and Wales were particularly hard hit by the Black Death, and mining villages in Pennsylvania and South Africa faced similar infection rates.
Places like Milan and Douai in Flanders were mostly spared from the ravages of the Black Death, despite being major hubs of commerce and industry at the time. In fact, only one household in Milan contracted the disease, and according to Douai chronicles the plague was successfully contained there. Milan would remain mostly plague free until 1400.
The death rate in the Italian city of Florence was 90%, and the French town of Caux in Normandy lost 66% of their population to the Black Death. While Europe was devastated by the plague, its average mortality rate was somewhere between 30 to 40%, a far cry from the hardest hit areas of France and Italy.
In rural communities hit hardest by the plague, bodies would be tossed into mass graves and covered in lime, their names lost to time thanks to a lack of record keeping. Funerals became rare, seeing as how if one member of a family contracted the plague, the rest died with them not long after.
1. The Most Effective Tool Against it was Quarantine
Much like today’s pandemic, communities that observed quarantine and social distancing saw cases of the Black Death taper off. Officials in cities like Milan and Venice enacted policies strikingly similar to ones taken in the 1918 Spanish Flu pandemic and of course today’s.
According to historians, the officials in these cities knew that they needed to handle goods with great care, because it was thought that the disease could spread on objects and surfaces. They also knew that person to person contact was one of the leading causes of the Black Death’s spread.
The Adratic port city of Ragusa (known as Dubrovnik in modern times) was the first to pass legislation leading to a mass quarantine. The legislation made it mandatory for all incoming ships and trade caravans to quarantine and be screened by physicians for signs of infection.
But even with this quarantine law, Ragusa continued to be hit by subsequent outbreaks in 1391 and 1397, because it was a major hub for commerce, making it impossible to wall it off from the rest of the world and the Black Death.
Venice, however, would use an entire island, known as Lazzaretto Vecchio to house people who had been infected by the disease.
Historians find these measures impressive, considering that humans would not discover the reason for the spread of infectious diseases until modern times.