Scientists uncover a tortured history of disease and death from the Middle Ages onward

On a hot afternoon in July 2012, Giuseppe Vercellotti was digging up bones near the wall of an abandoned medieval church here, thinking about getting a cold drink, when he heard his students call his name. Faces glistening with sweat, they told him that they had found something strange buried half a meter down. Vercellotti took a look and saw a layer of lime, used in ancient times to squelch the stench of rotting corpses. When he tapped the hard layer with his trowel, it sounded hollow.

“We immediately thought it was a mass grave,” says Vercellotti, a biological anthropologist at Ohio State University, Columbus, who co-leads a field school here. “We instructors were all excited and hopeful.”

But the students were apprehensive: “They all started talking about possible contagion,” Vercellotti says. Unconcerned, he leaned deep into the trench, where he got a whiff of a pungent odor and spotted an elbow bone poking out of the lime that had sealed it like a cast. The layer spoke of bodies tossed into a pit and hastily covered with lime. Could this trench hold victims of the Black Death, the plague that killed half of Europe in the Middle Ages?

It was the end of the summer field season. So the team carefully covered the trench with tarps and went home, hoping that excavations in 2013 would show that they had struck gold. They had come to expect extraordinary finds in the graveyard of the now decrepit Abbey of St. Peter, where a bountiful store of ancient skeletons was laid to rest in a single place over 1000 years, from the 11th to the 19th centuries.

The goal of the ongoing project is to read the history written in these bones: when and where these people were born, what they ate, what diseases they suffered and died from, and how their health varied by social class and over time. “This is a superb opportunity to learn about life in the medieval period and how it evolved and changed over that time and into the Renaissance and Industrial era,” says project co-leader Clark Spencer Larsen, a biological anthropologist at Ohio State.

Helped by locals who house and feed 30 students for 6 weeks each summer, the interdisciplinary team of 12 researchers is now in its third year of excavations. Their work is set apart not just by the extraordinary site but also by the variety of tools used to learn the secrets of the bones, from scanning them with 3D computed tomography to extracting isotopes from the teeth. In an unusual collaboration, this year the team brought along an ancient DNA expert to sample for ancient pathogens.

Because the abbey stood beside an ancient pilgrimage route, the results could help track the spread of disease through Europe. DNA from ancient microbes could also help today’s medical researchers keep one step ahead of fast-evolving diseases like cholera and influenza. “What you’re seeing at Badia Pozzeveri is hypothesis testing not only on bones, but also using pathogens and cultural factors,” says bioarchaeologist George Armelagos of Emory University in Atlanta, who is not part of the project. “It’s going to be the poster child for future work in bioarchaeology.”