Ancient DNA Reveals Unexpected Burial Practices in Medieval Sweden

A study of 142 skeletons from three medieval Swedish cemeteries reveals that adults and children buried together in the same grave were rarely close biological relatives. Published in Science Advances, the research challenges long-standing archaeological assumptions that collective burials in 10th- to 14th-century Scandinavia primarily represented parent-child relationships. Instead, genetic evidence suggests that these burial patterns were driven by religious norms, seasonal necessity, and social community ties.

Biological Kinship Versus Social Burial Norms

Archaeologists have long debated the nature of collective burials, where two or more individuals are interred in a single tomb. According to lead author Maja Krzewińska, a paleogeneticist at Stockholm University, the assumption that these pairs were immediate family members was largely incorrect.

The DNA analysis showed that while individuals buried together were often of the same sex—such as a woman with a girl or a man with a boy—they frequently lacked close biological ties. Researchers suggest several reasons for this practice:

* Religious Exclusion: Children who died before baptism were often ineligible for burial in consecrated ground. Interring them with an adult who was already entitled to a Christian burial may have served as a way to circumvent strict religious requirements.
* Seasonal Constraints: In medieval Scandinavia, winter burial was often impossible due to frozen ground. It is likely that some unrelated individuals were buried together in the spring after passing away during the winter months.
* Social Households: Medieval households were complex, often consisting of extended family, servants, and enslaved people. Membership in a local Christian community, rather than just biological lineage, may have dictated burial placement.

Kinship Groups and Pilgrimage at Västerhus

While many collective burials contained unrelated individuals, the study also identified evidence of multi-generational family plots. At the Västerhus cemetery, researchers mapped the kin group of an individual identified as “Lady 56,” a woman who died around the age of 30.

Archaeological findings at the site provided clear markers of status and belief. Lady 56 was buried with a scallop shell, a symbol of the apostle James, signifying that she had completed a pilgrimage to Santiago de Compostela in northwestern Spain. DNA analysis confirmed that her parents, brother, and daughters were all interred within the same cemetery, though they were placed in different locations.

The presence of a wealthy landowner’s farm at Västerhus from the 11th to 14th centuries likely influenced these burial patterns. The coexistence of both biologically related family plots and unrelated collective burials highlights the diverse social and religious factors that shaped death rituals in early Christian Scandinavia.

Understanding Medieval Burial Traditions

The use of ancient DNA has provided researchers with a definitive tool to test historical interpretations of burial sites. Anna Kjellström, an archaeologist at Stockholm University and co-author of the study, noted that these genomic insights finally allow for a direct examination of relationships that were previously only subject to speculation.

The study, titled “Equal in death: Ancient genomic analysis of children’s early Christian burials,” underscores that burial practices were not uniform. Different graves within the same region and time period often reflected distinct social priorities, ranging from the preservation of high-status family lineages to the practical integration of non-biological kin into the Christian community.