“The ways that social inequalities are manifested … put people at higher risk,” says Monica Green, an independent historian who studies the Black Death. “We should all be learning in our bones, in a way that will never be forgotten, why [the coronavirus pandemic] has happened the way it has.”

WHEN THE BLACK DEATH STRUCK, many places in Europe were already beleaguered. The late 13th and 14th centuries were a time of climatic cooling and erratic weather. Harvests had failed and famines had struck in the century or so before the pandemic emerged. In the Great Famine of 1315–17, up to 15% of the population of England and Wales died, according to historical records. As wages fell and grain prices soared, more people were driven into poverty. Household account books and records of payments to workers on English manors show that by 1290, 70% of English families were living at or below the poverty line, defined as being able to buy enough food and goods to not go hungry or be cold. Meanwhile, the wealthiest 3% of households received 15% of the national income.

Sharon DeWitte, a biological anthropologist at the University of South Carolina, Columbia, investigates how those famines and rising poverty affected people’s health by studying skeletons excavated from London’s medieval cemeteries. People who died in the century leading up to the Black Death tended to be shorter and more likely to die young than people who died during the two previous centuries. Those who lived in the century before plague also had more grooves on their teeth from disrupted enamel growth, a sign of malnutrition, disease, or other physiological stressors during childhood.

DeWitte lacks samples from the decades immediately before the Black Death, but historical evidence of the Great Famine and low wages until the 1340s make it likely that those trends continued right up until the pandemic struck, she says.

To see whether ill health made people more susceptible to plague, DeWitte turned to hundreds of skeletons excavated from East Smithfield. She calculated the age distribution of people in the cemetery, as well as the life expectancies of people with markers of stress on their skeletons. Her rigorous models show older adults and people already in poor health were more likely to die during the Black Death. Contrary to the assumption that “everyone who was exposed to the disease was at the same risk of death … health status really did have an effect,” she says.