The Black Death reflected in agricultural activity: analyzes of pollen deposits from 19 countries show that the worst known plague wave affected different areas of Europe very differently: while the Grim Reaper really raged in some regions, others were apparently affected surprisingly little. The exact reasons for the differences remain unclear. However, the researchers say that cultural, ecological, economic and climatic factors probably played a role in regional developments.
Today the Covid-19 pandemic is giving us a hard time. But much worse infectious diseases have raged in human history, above all the plague. Various waves of propagation have hit Europe, West Asia and North Africa. The so-called Black Death is considered to be the most momentous plague pandemic: Between 1347 and 1352 millions of people died and as a result there were many social ruptures in Europe. As a result, this epidemic has made a particularly strong impression on the memory of mankind.
Studies have already been able to identify the bacterial pathogen Yersinia pestis as the cause of the plague and rat fleas, which also attack humans, as important carriers. According to some estimates, the Black Death may have killed nearly half of Europe’s population. A comparatively even spread of the disease is sometimes assumed. However, there were already indications that clear regional differences existed. However, historical records and archaeological research paint an unclear picture of the true demographic impact of the disease in different areas of Europe.
Significant differences are emerging
In order to obtain new information on the plague mortality at that time, an international research team has now examined the development of agricultural activity in the relevant period. The scientists used analyzes of pollen deposits from the late Middle Ages as evidence: they examined 1,634 samples from 261 study locations in 19 European countries. This enabled the team to determine which crops were being grown in what quantities over the relevant time period, and whether wild plants were able to re-establish themselves in abandoned fields. This made it possible to draw conclusions about the extent to which agriculture was restricted during the pandemic and thus also how badly the respective region was affected by the plague.
As the researchers report, the results show that the plague raged more differently in different areas of Europe than previously thought. Scandinavia, France, southwest Germany, Greece and central Italy experienced a particularly sharp decline in agricultural activity. This fits with medieval sources reporting very high population losses in these areas. But it is now clear that this appeared to be in contrast to other regions: parts of Western Europe, including Ireland and the Iberian Peninsula, and areas of Central and Eastern Europe showed signs of continuity and even uninterrupted growth in agriculture. Apparently, there were no drastic population losses there.
Complex pandemic development
“The study thus refutes views about the Black Death that assume that Yersinia pestis was almost evenly distributed across Europe and that the pandemic had devastating demographic effects everywhere,” the scientists write. In addition to the insights into the spread of the plague, there are also indications for historians: “For regions such as Bohemia, Hungary and Poland, the results of the study reinforce the assumption that their heyday from 1350 has something to do with the absence of the Black Death could,” says co-author Martin Bauch from the Leibniz Institute for the History and Culture of Eastern Europe (GWZO) in Leipzig.
It is surprisingly clear how regionally different the impact of the pandemic was at the time. But why? “This significant variability in mortality has yet to be fully explained. However, local conditions probably had an influence on the spread, infection rate and mortality from the pathogen Yersinia pestis,” says senior author Alessia Masi from the Max Planck Institute for the Science of Human History in Jena and the University of La Sapienza in Rome. Apparently, the medieval plague outbreaks were also characterized by a dynamic in which cultural, ecological, economic and climatic factors in particular played a role.
The scientists hope that future studies will be able to elucidate how these variables interacted in the development of past pandemics – and thus possibly also how they shape current developments. First author Adam Izdebski from the Max Planck Institute for the Science of Human History also makes a specific connection to Covid-19: “What we experienced during the corona pandemic, we were also able to show for the plague outbreaks at that time: Pandemics are complex phenomena, which always have different regional and local characteristics,” the scientist sums up.
Source: Leibniz Institute for the History and Culture of Eastern Europe (GWZO), Max Planck Institute for the Science of Human History, specialist article: Nature Ecology & Evolution, doi: 10.1038/s41559-021-01652-4