The Black Death Wasn’t as Deadly as Previously Thought, Research Suggests

Ancient pollen deposits reveal that some areas of Europe may have experienced a ‘much lighter touch’ of the disease, according to the study

Two rats on the street eating crumbs
Flea-ridden rats in crowded medieval cities were the primary cause of Black Death infections in the 14th century, which historians believe killed off nearly half the European populaton. A new study argues, however, that the death toll may have in fact been way lower.  Alexander W Helin / Getty Images

New research shows the Black Death might not have been as deadly as previously thought, Carl Zimmer writes for the New York Times. Led by researchers from the Max Planck Institute for the Science of Human History, scientists analyzed pollen samples to determine if the Black Death did, in fact, kill half of Europe’s population between 1346 and 1352—a death toll that experts have long regarded as accepted scholarship. They published their findings last week in the journal Nature Ecology.

The team assessed pollen samples from 261 sites in 19 modern-day European countries to examine topographical changes between 1250 and 1450. The researchers write in The Conversation that durable pollen grains can last for centuries and differ in shape between plants. If, indeed, half of Europe’s population had died during the Black Death, the researchers would expect to see a change from agricultural pollen grains to those of trees and shrubs as fields were left to fallow as farmers died off.

“Half of the labor force is disappearing instantly,” study author Adam Izdebski tells the New York Times. “You cannot maintain the same level of land use. In many fields you would not be able to carry on.”

While some areas like southern Sweden, central Italy and Greece fit this pattern, other areas like Catalonia and Czechia showed no change in agricultural presence, according to The Conversation. Other areas like Poland, the Baltic countries and central Spain experienced an increase in agricultural expansion.

A regionally variable Black Death also fits with what modern scientists know about the spread of plagues, per The Conversation. The study notes that while the most prevalent form of Black Death spread came through infected rat flea bites, human overcrowding and unsanitary conditions in medieval cities likely contributed to accelerated spread.

These new findings are in direct opposition to many previously held beliefs about the impact of the Black Death–Ole Benedictow, one of the leading historians on the plague, recently estimated 65 percent of Europe’s population was wiped out by the plague. And despite the new study, John Aberth, author of The Black Death: A New History of the Great Mortality, tells the New York Times he doubts the conclusion of the study.

“[Europe was] highly interconnected, even during the Middle Ages, by trade, travel, commerce and migration,” says Aberth. “That’s why I am skeptical that whole regions could have escaped.”

However, other researchers say the study’s results match with their findings. Sharon DeWitte, a biological anthropologist with the University of South Carolina, found skeletal remains from London dating from that time period that support the idea of a more modest death toll, writes the New York Times. And Joris Roosen, head of research at the Center for the Social History of Limburg in the Netherlands, found similar results in his analysis of inheritance taxes in the Belgian province Hainaut.

The discrepancies might be due in part to the sources dating from that time, which come largely from state or church officials in urban areas that would have been impacted more heavily by the plague, writes the Independent’s Vishwam Sankaran. While the researchers are currently unwilling to put out an approximation of what percent of Europe was actually affected by the plague, they say that they stand by their results. “It should prevent us from making quick generalizations,” they write in the Conversation, “about the spread and impact of history’s most infamous pandemic.”