Plague’s Last Swiss Victims Found Under a Concert Hall

In the spring of 2016, workers and archaeologists broke ground beneath the Stadtcasino concert hall in the heart of Basel, Switzerland — one of Central Europe’s most prosperous cities. What they uncovered would take a decade to fully understand: a layered cemetery of 279 individuals, tucked inside the cloister garden of the old Franciscan Barfüsserkloster monastery, founded in 1250. Among the graves, four clustered pits stood apart. Designated graves 229 to 232, they held fifteen people interred together, apparently in a crisis. Published in April 2026 in the journal Antiquity, a new study by Laura Rindlisbacher and colleagues from the University of Basel and Kiel University has now revealed exactly who those people were, how they lived, and how they died.

Map – Basel

A City That Would Not Close Its Gates

To understand what these burials mean, you must first understand Basel’s peculiar and unfortunate relationship with plague. During the Early Modern period, roughly 1500–1750, bubonic plague revisited European cities with grim regularity. Basel sat at a crossroads. Its merchant council, determined to protect trade income, repeatedly refused to close the city gates even as infected travellers poured through them. Historians believe many Swiss and Italian outbreaks entered the continent through Basel along the Rhine trade routes. The city paid dearly for this commercial pragmatism: its annals record wave after wave of pestilence.

The city’s own physician, Felix Platter (1536–1614), witnessed seven plague epidemics across his lifetime and left meticulous records of deaths and recoveries during the 1610/1611 outbreak, noting residential addresses and categorising victims by age and sex. Those records, held in the Basel State Archives, have now become essential companions to the bones.

From Monastery to Hospital to Emergency Cemetery

After Basel adopted the Reformation and the Franciscans departed in 1529, the monastery complex passed into the control of the city’s Bürgerspital — the municipal hospital, itself founded before 1265. The cloister and the monks’ small hermitages were repurposed as a kind of asylum, housing individuals whom the hospital council deemed to need special supervision. At times, the site functioned explicitly as a plague hospital.

Burial in the cloister garden began in the post-Reformation period. Archaeologists identified two main burial phases: an older group oriented east–west, characterised by shroud burials in simple earthen pits, and a later, north–south phase including both single graves and multiple burials, many with coffin nails, coins, clay pipes, and sewing needles among the grave goods. It is from this later phase that graves 229–232 emerge.

A Pipe, a Stamp, and a Date

The detective work of archaeology often turns on small things. In grave 229, a small white earthenware clay pipe was found resting near the hip of individual 229.2. Under examination, a maker’s stamp on the pipe’s heel revealed a crowned rose and the monogram RW — the mark of Reichard West, a pipe maker documented in council minutes from Mannheim, Germany between 1673 and 1675, who died around 1675/1676. Since clay pipes were fragile and typically discarded within three years of purchase, this single object provided both a terminus post quem and a terminus ante quem for the burial: the individual was interred sometime between roughly 1650 and 1678.

That date range intersected with something the Basel archives recorded clearly: a plague epidemic ravaging Switzerland between 1665 and 1670 — the last one ever recorded in the country. The hospital’s own expenditure books showed a peak of 76 burials in 1667, compared with the usual 10–60 per year. The ordinary rhythm of death had broken down.

From left to right, graves 229, 230, 231 and 232 during excavation, upmost layer (figure © Archäologische Bodenforschung Basel-Stadt; photographs by A. Jost).

Fifteen Individuals: Who Were They?

The fifteen individuals in graves 229–232 ranged in age from a child of three or four years to older adults. The average age at death across the group was just 17.7 years. Eleven of the fifteen were under twenty at the time of death. Of the seven individuals for whom biological sex could be determined, five were identified as likely male and two as likely female; the remaining eight — mostly children — could not be assigned a sex from skeletal evidence alone.

This demographic profile is immediately striking. In a normal cemetery, children and the very young dominate not because they died from a specific catastrophe, but because high birth rates in pre-industrial societies naturally produce high infant mortality. But this group does not fit that pattern. The over-representation of adolescents — an age group with low mortality in normal populations — points instead to a sudden catastrophe. The absence of any perimortem injuries rules out warfare. All signs pointed to epidemic disease.

The Bones Tell a Harder Story

Before the plague took them, these individuals had not lived easy lives. Osteoarchaeological analysis revealed a startling density of health problems, particularly given how young most of the group was.

Every individual whose teeth survived — eleven of the fifteen — showed at least one cavity. Of 310 preserved teeth examined, 64 were affected by caries, and four individuals had already lost teeth before death while also suffering from active dental abscesses or cysts. Eleven individuals showed enamel hypoplasia: those characteristic bands of thinned or pitted tooth enamel that form when the body is under severe physiological stress during childhood, from malnutrition, illness, or both. Sixty-one per cent of all teeth examined bore these stress markers. Two individuals showed dental wear consistent with using their teeth as tools, suggesting occupational labour of a manual kind. Two others showed healed fractures, and the group as a whole carried an average Index of Skeletal Frailty of 3.3, a relatively high figure.

Degenerative spinal conditions (spondyloarthrosis deformans) appeared in all individuals, including those under fifteen. Seven showed signs of anaemia or iron deficiency in the bony orbits of the eye sockets or the femoral neck. The picture that emerges is of people who had spent their short lives working hard, eating poorly, and weathering repeated illness — before the plague found them.

What They Ate: Stable Isotope Analysis

Stable carbon and nitrogen isotope analysis of rib samples from eleven individuals offered a window into nutrition during the final years of life. The results were striking in their uniformity. All individuals shared very similar isotopic signatures, clustering around diets dominated by C3 plants — cereals such as wheat and rye — along with sheep, goat, and pig. There was almost no evidence of millet (a C4 plant), and the low nitrogen values excluded significant consumption of fish, chicken, or suckling animals.

Crucially, there was no meaningful difference in diet between adults and children, or between males and females. The group appears to have eaten from the same, relatively modest, table. Compared to Basel’s faunal reference data from the eighteenth century, the individuals consumed some animal protein, but the overall diet sits at the lower end of the range for the region. This was not the diet of Basel’s prosperous merchant families.

The Pathogen Confirmed

The most compelling evidence came from ancient DNA analysis. Eleven teeth, sampled from ten individuals, underwent high-throughput shotgun sequencing. The results were unambiguous: five individuals tested positive for Yersinia pestis — the bacterium responsible for bubonic, pneumonic, and septicaemic plague.

One individual, 229.2 — the same person buried with the Mannheim clay pipe — yielded particularly well-preserved pathogen DNA. Deep sequencing covered 89 per cent of the Y. pestis chromosome and between 81 and 94 per cent of its three plasmids. The damage patterns in the ancient DNA were consistent with genuine degraded material, not contamination. Phylogenetic analysis placed the Basel strain within a cluster alongside strains recovered from plague burials in London (1560–1635) and Marseille (1720–1722), confirming its place within the post-Black Death lineage of the bacterium. The strain also showed a characteristic depletion in the pla gene region — a feature noted in post-1353 strains — which researchers speculate may have moderated, though clearly not eliminated, the disease’s transmissibility.

Inequality in the Face of Death?

The study’s title poses a question: Were all people truly equal in the face of this epidemic? The evidence suggests they were not. The Bürgerspital served only full citizens of Basel or those with employer-backed financial support. Domestic servants originating from the countryside were reportedly expelled from the city when they fell ill. The individuals in graves 229–232, with their histories of childhood stress, hard labour, dental disease, and modest diet, appear to belong to Basel’s labouring poor — people who lived on the margins of the city’s institutional protections.

Felix Platter’s statistical records from the 1610/1611 epidemic — an earlier but instructive outbreak — show that in Basel’s suburban districts, roughly 77 per cent of those who fell ill were under twenty years old, and children bore a lethality rate of around 72 per cent, compared with 54 per cent for adults. The group from graves 229–232, with their average age of 17.7, aligns almost exactly with this vulnerable demographic.

The researchers frame this in terms of what they call “prior experiences affecting differential mortality” — in plain language, the physical and social disadvantages accumulated across a lifetime that made some bodies more vulnerable when plague arrived. Poor childhood nutrition, repeated illness, hard physical work, and social exclusion did not cause plague, but they shaped who died from it.

A Mirror for Our Own Times

The authors open their study with a deliberate observation: the COVID-19 pandemic sharpened public awareness of the relationship between socioeconomic status and vulnerability to infection. The Basel plague burials suggest this relationship is not a modern discovery. It is as old as epidemic disease itself.

Seven centuries after the first great European plague pandemic and three and a half centuries after the last Swiss outbreak, fifteen individuals in a former Franciscan cloister garden in Basel still have something to say. They speak through their teeth, their bones, their isotopes, and their ancient DNA: that in the face of death, people were not equal. Some arrived at the plague already worn down by the weight of poverty, childhood hardship, and labour. The epidemic found them, as epidemics tend to do, where the margins were.