Lewis, an archaeologist and professor at the University of Lincoln, is looking for bits of broken pottery from around the time of the Black Death — fragments that can illustrate how communities were affected by the illness that swept through some six and a half centuries ago. In a paper published in the journal Antiquity this week, she reports that her discoveries demonstrate a 45 percent population decline between the century just before the plague hit England and those after.
The devastation, she wrote in her paper, is "evident on an eye-watering scale."
The study backs up contemporary accounts of the pandemic's impact on mid-14th century England. At St. Mary's Church in the village of Ashwell, an anonymous hand engraved the phrase "wretched, terrible, destructive year, the remnants of the people alone remain," to describe what unfolded in 1349. Until the last 50 years or so, historians believed that the devastation was as awful as described and accepted that the plague probably did kill a quarter to a half of Europe's inhabitants and instigate widespread social upheaval.
But solid, scientific evidence for that was hard to come by. Centuries of excavation haven't revealed the mass graves that contemporaries wrote about, and because of shifts in taxation strategy that occurred around the same time, there are no census records to back up the reports. Besides, the notion of such a completely catastrophic pandemic challenges researchers' belief that societies are able to self-correct when outside forces threaten them. After all, even the worst pandemics of modern times — for example, the Spanish flu in the early 20th century — killed no more than 3 percent of the world's population. Perhaps tales of the 14th-century bacterium wiping out half of civilization were a teensy bit exaggerated.
Or perhaps not.
Lewis's study, which uncovered some 10,000 shards of pottery from 50 towns across a wide swath of eastern Britain, found evidence of dramatic population shifts in almost every one of those communities. Human communities "shed pottery like dandruff," she said. Much as fossil records illustrate the appearance and extinction of species, pottery records show the rise and fall of towns.
With the help of community members (including hundreds of school kids) overseen by professional archaeologists, Lewis and her colleagues excavated some 2,000 one-meter-square pits in church yards and front gardens across the region.
Pre-Black Death pottery — easily identifiable by its dull, gray-brown coloring and sandy texture — was abundant in every spot Lewis searched for it. But the pottery of the next 200 or so years, when technologies changed to make vessels thinner and lighter in color, was scattered far more sparsely. About 90 percent of towns saw a drop, some of them by more than half. On average, there was about 45 percent less pottery after the plague period than before it. This find seems to support the written accounts that claim death tolls somewhere between a quarter and half of the population.
The fact that shard levels remained constant in roughly 10 percent of towns suggests to Lewis that the shift was indeed due to population decline and not some other factor. If people had simply stopped using as much pottery, she said, then the number of shards would have fallen by a more or less equal amounts everywhere. The varying degrees of decline illustrate how different villages were affected.
"For the first time we can measure this impact and map it to know exactly what the decline was and where it happened," Lewis said.
The villages that did prove resilient were ones whose economies didn't wholly depend on agriculture. Centers of trade fared relatively well after the plague, even if they'd lost many of their inhabitants, because their main industry didn't require large numbers of people in order to sustain it. But farming villages, where there was no one left to plow the fields or harvest the crops, fell into deep decline. For many, it would take centuries to even begin to recover.
Lewis hopes to use the same technique to map the devastation of the Black Death in towns throughout Britain. She hopes her research will give a "baseline understanding" to researchers studying population shifts in the wake of the disease.
"Until we know what happened we can't understand why it happened," she said. "This is beginning to give us a clearer picture."