DNA from 142 medieval Swedish burials shows people sharing graves were rarely relatives

At Västerhus, a churchyard in Jämtland, only 3 of 25 graves holding more than one person contained first-degree relatives. That count comes from the genetic analysis of 142 medieval and late Viking Age Swedish burials, led by Maja Krzewińska at Stockholm University, and it overturns an assumption that most archaeologists carried into their field notes: that an adult and a child in one grave were parent and child.

Krzewińska describes the assumption as a common default, and says that in most cases the genetics did not bear it out.

The 142 burials and what they showed

The study, from the university’s Centre for Palaeogenetics, where ancient DNA is extracted and sequenced from bone and teeth, sampled 142 individuals from three sites: Sigtuna near Stockholm, Västerhus in Jämtland and Fjälkinge in Skåne. More than 60 were children and adolescents, according to the Stockholm University release, in which Krzewińska says archaeologists often assume that adults and children sharing a grave were parents and children or other close family, and that in most cases the study found otherwise. ScienceDaily’s repost of the release on 25 September adds that close biological relatives were surprisingly uncommon among people placed in the same grave.

Archaeology Magazine gives the breakdown: 74 adults and 68 children or teenagers, drawn from 27 single graves and 50 multi-occupant graves. The paper itself, in Science Advances, appeared in July; the September coverage is a second wave of attention, not a new result.

Counting relatives, grave by grave

The numbers are specific. Medievalists.net reports that close kinship turned up in 3 of 25 multiple burials at Västerhus, about 12 per cent, and in only 2 of 16 at Sigtuna. Across the dataset, the genetic diversity inside shared graves matched or exceeded that of single burials, which is the pattern expected if the dead were buried together because of something other than blood.

What replaced kinship as the organising principle is left open. The study points to social, religious or local customs, with household membership, community ties and status as candidates alongside kinship, and the release makes no attempt to name a single rule. The family in the shared grave, in other words, was often a family by arrangement.

The practical consequence is for excavation reports. A woman buried with an infant at her side is easily written up as a mother and child, and the Västerhus and Sigtuna counts show how often that label would be wrong without a laboratory test. Krzewińska’s team treats biological kinship as one factor among several, so a shared grave now reads as evidence of a social bond that has to be established, not assumed.

The sampling matters to how far this can be generalised. Västerhus sits far to the north in Jämtland, Sigtuna is a town near Stockholm, and Fjälkinge lies in the south of Skåne, so the pattern is not a feature of one region. The three cemeteries come from the late Viking Age and the medieval period, when churchyard burial was becoming the norm and graves were being reused or shared.

Children, sex and one woman with a scallop shell

DNA also settled the sex of the youngest burials, which skeletons rarely do. Anders Götherström, professor of molecular archaeology, said that children were not treated as a separate category and appear to have been handled in death by the same social and religious principles as adult men and women. The release adds that the pattern shows gender identity was recognised early in life. At Västerhus, boys and girls lay on the same sides of the churchyard as men and women. Medievalists.net counts 28 adult-child graves, 17 of them same-sex pairs, with four infant girls at Västerhus buried with males in male areas as an exception.

One case shows how little a grave can reveal without genetics. Sex-sorted burial, the shared grave and the gendered layout of a churchyard are all visible to a trowel; the family trees behind them are not, and the study measures that gap at three Swedish sites.

The best-known individual is Lady 56, a woman from the Västerhus cemetery who died before 30 and was buried with a scallop shell, the emblem of pilgrimage to Santiago de Compostela. DNA linked her to her parents, a brother and two daughters, all buried elsewhere in the same Jämtland cemetery. The shell suggests she travelled thousands of kilometres across medieval Europe and came home, and Medievalists.net presents her as evidence that Scandinavian women took part in long-distance Christian travel. Her family was real; it was just not in her grave.

Why the other pairings were made remains unexplained. Whether household, parish or some other bond placed a child beside an unrelated adult is not settled in the release, and the DOI-linked paper in Science Advances is where any grave-by-grave reasoning would have to appear.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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