The remains of at least 48 people who died of plague have been found at an unprecedented English site.

Archaeologists digging in the English countryside have discovered the first known Black Death mass grave in rural England — a sign of a community overwhelmed by the dead.

While excavating the grounds of Thornton Abbey in Lincolnshire, UK, Hugh Willmott at the University of Sheffield, UK, and his colleagues found a large collective burial site holding the remains of at least 48 people. Although epidemic-related mass graves had previously been documented in London, this was the first uncovered in rural England.

The bones date to the fourteenth century, a time period encompassing one of England’s major outbreaks of bubonic plague, also known as the Black Death. Analysis of DNA from the skeletons confirmed the presence of Yersinia pestis, the bacterium that causes plague. Christian burial rites were highly prized in medieval England, so the presence of a mass grave suggests the desperation of those spared by the epidemic.

Further genetic testing of the Y. pestis pathogen from the skeletons, the researchers say, could help to reconstruct the spread of the Black Death across the country.