Scientists analyzed DNA from 142 people who lived during the late Viking Age and Middle Ages. The group included more than 60 children and adolescents recovered from multiple graves at Sigtuna, near Stockholm, Västerhus in Jämtland, and Fjälkinge in Skåne.

Shared Graves Were Often Not Family Graves

The genetic evidence revealed that close biological relatives were surprisingly uncommon among people placed in the same grave. This was true even in cemeteries where researchers found many biological family connections among the wider population.

"We often assume that adults and children sharing a grave were parents and children or other close family members. In most cases, that was not what we found," says Maja Krzewińska, Centre for Palaeogenetics, Department of Archaeology and Classical Studies, Stockholm University, lead author of the study.

The findings indicate that decisions about who was buried together were often shaped by more than close biological relationships. Social, religious, or other community factors may also have played an important role.

"Archaeologists have debated the relationships between people buried together in this type of grave for a long time. Ancient DNA has finally given us the tool we have been waiting for to test these interpretations directly," says Anna Kjellström, researcher at the Department of Archaeology and Classical Studies, Stockholm University.

Children Followed Adult Burial Customs

The DNA analysis also provided new clues about childhood in early Christian Scandinavia. Ancient DNA allowed researchers to determine the biological sex of children whose remains were too young for sex to be identified reliably from their bones.

The burial patterns showed that boys and girls often followed the same cemetery customs as adult men and women. At Västerhus, for instance, men and women were generally buried on different sides of the churchyard. Boys and girls were placed according to that same pattern.

The researchers say this suggests that gender identity was recognized from an early stage of life and was reflected in burial practices.

"The children were not treated as a separate category. In death, they appear to have been treated according to the same social and religious principles as adult men and women," says Anders Götherström, Professor of Molecular Archaeology, Centre for Palaeogenetics, Department of Archaeology and Classical Studies, Stockholm University.

DNA Reconstructs One Medieval Family

Among the people buried at Västerhus, researchers also reconstructed the story of an especially notable family.

A woman identified as Lady 56 was genetically connected to several other people buried in the churchyard. DNA linked her to her parents, her brother, and two daughters. But evidence from her grave suggests that her life may have stretched far beyond the local community in Jämtland.

Lady 56 was buried with a scallop shell, an unusual object to find in a medieval Scandinavian grave. The shell was also a widely recognized symbol associated with pilgrimage to Santiago de Compostela in northwestern Spain.

Its presence suggests that Lady 56 may have completed one of medieval Europe's most famous pilgrimages, traveling thousands of kilometers across the continent to the western edge of Christian Europe before eventually returning home.

Lady 56 died before the age of 30. Her parents, brother, and daughters were also buried in different parts of the same cemetery in Jämtland.

Ancient DNA Opens a Window Into Medieval Society

Together, the findings show how archaeogenetics can reveal far more than biological family relationships. By combining ancient DNA with archaeological evidence, researchers can begin to reconstruct how medieval communities were organized, how children were treated, how religious customs shaped burial practices, and how people related to one another in both life and death.