It was the worst pandemic in human history – in the mid-fourteenth century a bubonic plague would spread throughout Asia, Europe and North Africa. One big question about the Black Death is how many people were killed?
The answer to this is both complicated and, ultimately, we don’t know. People have taken guesses, but there are many problems with these estimates. For example, if people search for an answer online, they will probably turn to Wikipedia. And they get this information about the Black Death:
the most fatal pandemic recorded in human history, causing the deaths of 75–200 million people, peaking in Europe from 1347 to 1351.
Even though both the high and low numbers given here are huge, there is quite a big difference between them. It also lacks a key piece of information – how many people were actually alive at this point in history. Therefore, how are we to know what percentage of people died during the Black Death?
What we do have is a lot of studies and estimates for various places. Turning back to Wikipedia, we get this:
In crowded cities, it was not uncommon for as much as 50% of the population to die. Half of Paris’ population of 100,000 people died. In Italy, the population of Florence was reduced from between 110,000 and 120,000 inhabitants in 1338 to 50,000 in 1351. At least 60% of the population of Hamburg and Bremen perished, and a similar percentage of Londoners may have died from the disease as well, leaving a death toll of approximately 62,000 between 1346 and 1353. Florence’s tax records suggest that 80% of the city’s population died within four months in 1348] Before 1350, there were about 170,000 settlements in Germany, and this was reduced by nearly 40,000 by 1450.
All these numbers sound impressive but a closer look shows they are not particularly reliable. For example, Paris is said to have lost half its population of 100,000. However, estimates of the French city’s population before the plague range between 80,000 and 200,000. Meanwhile, our best source for the Black Death in Paris is the Chronicle of Jean de Venette, which offers this statement:
In many places not two out of twenty remained alive. So high was the mortality at the Hotel-Dieu in Paris that for a long time, more than five hundred dead were carried daily with great devotion in carts to the cemetery of the Holy Innocents in Paris for burial.
While certainly it presents a devastating picture, it is problematic to use this source to help make a claim of 50,000 people dying. Perhaps 500 people died every day for a hundred days, but it could be an exaggeration. Is Jean de Venette remembering the events as worse than they were? Or maybe he is being dramatic for his readers? Elsewhere in his chronicle he talks about how France suffered through the years 1348 and 1349, noting that “many country villages and many houses in good towns remained empty and deserted. Many houses, including some splendid dwellings, very soon fell into ruins. Even in Paris several houses were thus ruined, though fewer here than elsewhere.” So Parisians both suffered a lot from the plague but also not that bad.
One can find problems with the other estimates too. London is said to have had around 60% of its population killed in the plague, but I came across a letter in 1357 from London’s mayor and alderman specifically stating how they “endured a great pestilence which had emptied the city of more than a third of its inhabitants and impoverished the rest of them.” That piece of evidence cannot match with any calculation of 60%.
There have been several major studies that have tried to estimate the toll of the plague. Philip Ziegler’s 1969 work The Black Death was one of the first attempts to assess the number of deaths that took place during the pandemic. With his focus on England, he came up with an estimate that the country was home to 4.2 million people before the plague and that between 34% and 45% died from the disease. Expanding his ideas to the rest of Europe, Ziegler writes:
To maintain that one European in three died during the period of the Black Death can never be proved but, equally, cannot be wildly far from the truth. Further than that, in the present state of knowledge, one cannot go.
Since then, estimates seem to have gone upwards. In John Aberth’s book, The Black Death: The Great Mortality of 1348–1350, he believes that half the population died. Then we have the research by Ole J. Benedictow, most recently seen in the 2021 book The Complete History of the Black Death. He examined practically every region of Europe and found many examples of high death tolls. So when he comes to answer the question – How many people died in the Black Death? – Benedictow writes:
The size of Europe’s population immediately before the arrival of the Black Death can be estimated at roughly around 80 million inhabitants. A mortality rate of 65% indicates that roughly 52 million died by or in connection with the Black Death and that there were 28 million survivors.
This is not the end of the debate. New evidence is constantly emerging, such as an article published last year in the journal Nature Ecology & Evolution. A team of researchers did not look for dead bodies, but rather pollen. Using 1,634 pollen samples from 261 sites across Europe, they could see if these areas had changed before and after the Black Death – if the pollen revealed crops were still being planted in abundance, it would mean that the area had not been deeply affected. However, if it changed from crops to farming animals (which required less labour) that could suggest a decline in population. And if the land was quickly reverting to forest and scrubland, this could mean that it was abandoned altogether.
Their results show a wide variation throughout Europe – some parts were hit hard by the Black Death, while others seemed to have suffered very little. For example, the port cities of northwest Italy were among those reported to have many deaths. Meanwhile, the situation in the interior of that region saw no noticeable changes, at least when it came to pollen. The researchers conclude:
This significant variation in Black Death mortality may be explained by the pathogen’s entanglement with a dynamic nexus of climatic, cultural, demographic, ecological and societal factors that determined its prevalence and the pandemic’s mortality in any given region. That the pandemic was immensely destructive in some regions, but not all, falsifies the practice, common in Black Death studies, of predicting one region’s experience on the basis of another’s.
The study would also suggest that the high death rates proposed by Benedictow and others might be over-exaggerations, perhaps by focusing on towns and cities too much while neglecting that the vast majority of medieval Europeans lived in rural areas where they could have been more isolated from an outbreak of the plague.
We can say that tens of millions of people died when the Black Death struck in the years 1347 to 1352, but did it kill a third, half, or even two-thirds of the population? We do not know yet. As new research is done and our understanding of the pandemic grows, we might become more certain. And there are plenty of avenues for new research – scholars are just beginning to look at evidence of the plague in Asia, the Middle East and Africa. Environmental studies can offer many insights too.
With modern society just emerging from the Covid pandemic, our understanding of the spread and mortality of these large-scale events is expanding. They may also help us learn more about past pandemics and just how deadly the Black Death was.
Top Image: Map showing the spread of the Black Death in Europe between 1346 and 1353 – Image by Flappiefh / Wikimedia Commons