Researchers from the Catholic University of Leuven (KU Leuven) have discovered direct evidence of the Black Death in medieval Flanders by analysing the genetic remnants of 400 skeletons buried in Sint-Truiden between the 8th and 18th centuries.
This was the largest DNA study of its kind on skeletons from a medieval cemetery.
Archaeological excavations in 2019 uncovered over 3,000 skeletons beneath the Groenmarkt in Sint-Truiden, a site that served for centuries as the burial ground for the Church of Our Lady, near the Abbey of Saint Trudo.
KU Leuven researchers selected 400 of the skeletons for DNA analysis, based on their position in the burial field and the period they were interred.
This enabled geneticists to prove for the first time that the plague afflicted Flanders in the 14th century, although no written records mention it in Sint-Truiden during this period.
The DNA of the plague bacterium, Yersinia pestis, was found in five individuals from the 14th century, out of a total of 50 from that period.
The findings also offer insights into the population structure during the Middle Ages. Before 1200, the genetic diversity of the population was significantly greater than after this date.
Interestingly, the presence of Irish or Scottish individuals was also detected: the DNA profiles of five individuals closely matched those of contemporary Irish or Scottish people. After 1200, the population became more homogeneous.
“Despite trade contacts, for example with the Spanish, there were few or no traces of distant migrations,” says doctoral student Owyn Beneker, who conducted the laboratory work. “The DNA of late medieval Sint-Truiden residents closely resembles that of present-day Limburg residents.”
