Swedish DNA: ancient origins from Baltic foragers to the eastern Viking routes

What are the ancient origins of Swedish DNA? A two-rooted forager base, a thousand years in which Funnel Beaker farmers and Pitted Ware hunters lived side by side without merging, a Battle Axe arrival about 2800 BC that set the steppe-heavy Bronze Age profile, and a Viking Age whose traffic ran east across the Baltic and back. Ancestrify models each era from your raw DNA.

Sweden is the Baltic face of Scandinavia, and its ancient DNA reads differently from Denmark's for that reason. Where the Danish transect shows two clean replacements, Sweden's record shows foragers holding on beside the farmers for a millennium, a Battle Axe horizon that arrived already blended, and a Viking Age that faced east toward the river routes rather than west toward the Danelaw. This guide covers what is specific to Sweden inside the wider Scandinavian story: the Gotland hunters, the eastern routes, the north to south structure of the modern country, and the Sámi as a distinct population with their own history.

The short answer: Swedish ancestry stands on Scandinavian hunter-gatherers who entered through two doors, was reshaped by Funnel Beaker farmers about 4000 BC while Pitted Ware foragers persisted on the Baltic coast, and was reset by the Battle Axe culture about 2800 BC into the steppe-heavy Nordic Bronze Age profile. The Viking Age brought eastern Baltic and other foreign ancestry into Sweden, a share that later centuries thinned. Modern Sweden carries a real north to south cline, with ancestry related to Finnish and Sámi populations rising toward the north, while the Sámi themselves are a separate population with Siberian-related ancestry.

Two doors into a thawing peninsula#

The oldest Swedish genomes belong to the Scandinavian hunter-gatherer group, and the Mesolithic study that sequenced them found a population that was not simply the western European forager type moved north. Western hunter-gatherer ancestry came in from the south as the ice retreated; eastern hunter-gatherer ancestry came in from the northeast, along the ice-free Norwegian Atlantic coast, and the two met and mixed in the middle of the peninsula. Genomes from Motala in Östergötland and from Stora Förvar on Gotland carry that mixed signature, and they also carry light skin and eye pigmentation variants at higher frequency than either source population, a high-latitude adaptation the authors argued had already been selected for by then.

This is the forager base under every later Swedish genome. It is a trace today, but a trace with a distinct Scandinavian flavour.

Farmers and hunters, a thousand years side by side#

Sweden's Neolithic is the one that overturned the idea of a simple farmer replacement. In 2012 a Funnel Beaker farmer from Gökhem in Västergötland and three Pitted Ware hunters from Ajvide on Gotland, buried within a few centuries of each other about 5,000 years ago, were shown to belong to genetically different populations: the farmer resembled southern Europeans, the hunters resembled no modern population closely. The Neolithic farmers had arrived about 4000 BC with Anatolian-derived ancestry, and the hunters, with their seal-hunting economy and pit-decorated pottery, held the Baltic coast and islands beside them for a thousand years.

The follow-up in 2014 sharpened the point. Sweden's farmers carried hunter-gatherer admixture, but the Pitted Ware hunters carried no farmer admixture in return. The mixing ran one way. Gotland's foragers remained a separate population until they disappeared in the third millennium BC.

The Battle Axe culture arrives already mixed#

Sweden's version of the Corded Ware horizon is the Battle Axe culture, and its people appear about 2800 BC. Genomes from Battle Axe burials in Sweden and Estonia carry the steppe-derived ancestry that characterises Corded Ware populations across northern Europe, alongside farmer-related ancestry. The study that sequenced them found that this blend matched Corded Ware groups on the continent, which points to a population that arrived in Sweden already mixed, rather than one that formed on Swedish ground when steppe migrants married into the local Funnel Beaker communities. The paternal lineages of the Battle Axe men belong to R1a, the signature of the Corded Ware world.

From that arrival the Swedish profile is set: steppe-derived ancestry as the largest component, farmer ancestry second, a forager trace beneath. It is the same recipe that the Bronze Age transect reads across Scandinavia, and the I1 expansion that dominates Swedish paternal lines today dates from it.

The long stability, and the Viking Age that ran east#

The Nordic Bronze Age of rock carvings and bronze hoards, and the Iron Age of the Vendel boat graves, add texture without changing the recipe. Roman Iron Age genomes from Öland and central Sweden sit where the Battle Axe people left them.

The Viking Age is where Sweden's story diverges from Denmark's and Norway's. Swedish routes ran east: across the Baltic to Estonia and the Gulf of Finland, and down the rivers into what became Rus'. The Viking-world genomes (our full write-up) found a boat burial at Salme in Estonia whose crew was Swedish-like in ancestry and included close relatives buried together, and they found eastern Baltic ancestry inside Sweden, above all on Gotland, the island that sat in the middle of the trade. The town of Sigtuna, the first Swedish royal centre, was a mixed population by ancestry and by isotopes: a large share of the people buried there had grown up elsewhere. Sweden imported as it exported.

From the Viking Age to the modern cline#

The transect that runs from the Roman Iron Age to the present makes two findings that matter for Swedish genomes. First, the Viking Age inflow from the British Isles, the eastern Baltic and southern Europe was larger in Viking-Age individuals than it is in modern Swedes: the broadening was real but was only partly carried forward. Second, present-day Sweden shows a north to south gradient of ancestry related to Uralic-speaking populations, rising toward Norrland. The medieval centuries added a German layer through the Hanseatic towns, and Forest Finns settled the woodlands of Värmland and Dalarna in the sixteenth and seventeenth centuries, another eastern thread in the weave.

A nationwide genomic study of Sweden found real structure inside what looks on a map like one population. Southern and central Swedish counties form a tight cluster that overlaps with Danish and Norwegian averages. The northern counties, Norrbotten and Västerbotten above all, stand apart, pulled toward Finnish and Sámi populations by centuries of settlement and marriage across the Gulf of Bothnia. The cline is one of the cleanest in Europe on a PCA view: a Swedish genome from Skåne and one from Tornedalen can be closer to their nearest foreign neighbours than to each other.

The Sámi and the north#

The Sámi are the indigenous people of northern Fennoscandia, and their genome is a separate story rather than a northern variant of the Swedish one. Ancient genomes from Bolshoy Oleni Ostrov on the Kola Peninsula, about 1500 BC, show that Siberian-related ancestry had already reached the far north of Europe by the Bronze Age, and Iron Age individuals from Levänluhta in Finland carry it in a profile closer to modern Sámi than to modern Finns. The Sámi today carry that Siberian-related ancestry at the highest level of any population in Europe, alongside a European base, with distinctive maternal lineages such as U5b1b and V and paternal N-M231 lineages.

In Swedish genomes from the north, Sámi-related ancestry is a measurable component that grades southward. That is a population statement about a cline, not a label for any individual, and a formal model treats a Sámi-related source as one hypothesis to test among others.

Reading a Swedish genome with qpAdm#

Sweden is well served by references at every era, and a deep-era model with a Scandinavian forager source, an Anatolian-derived farmer source and a steppe source fits most kits cleanly. A proximal model from Nordic Bronze Age sources usually explains a southern or central Swedish kit with nothing else.

The sharp questions are regional. Does a kit require a Finnish-related or Sámi-related source beyond what Nordic Bronze Age sources explain? That is the northern question, and it is a clean formal contrast because Siberian-related ancestry is easy to detect against the right outgroups. Does a kit need an eastern Baltic source, the Gotland and Viking Age question? Does it need a British-Isles source, the inflow the Viking Age brought everywhere in Scandinavia? Each answer comes with a p-value and a standard error, and a rejected model is as informative as an accepted one when the sources are close kin.

Frequently asked questions#

Are Swedes descended from Vikings?#

Swedish genomes descend mostly from the Bronze Age population that was in place two thousand years before the Viking Age, and that population was the Viking-Age population too. The Viking Age added ancestry from the Baltic and elsewhere rather than creating a new Swedish gene pool.

Do Swedish people have Finnish DNA?#

In the north, measurably: the counties along the Gulf of Bothnia carry Finnish-related and Sámi-related ancestry that grades away southward. In southern and central Sweden the Finnish-related share is small, and the Forest Finn settlements of Värmland are the exception that proves the pattern.

Are Swedes genetically different from Norwegians and Danes?#

Distinguishable at population scale, overlapping individually. Sweden leans Baltic, Denmark leans continental, Norway leans Atlantic, but all three share the same three prehistoric layers in nearly the same proportions. The sharp Nordic boundary runs between Sweden and Finland, not between Sweden and its Scandinavian neighbours.

Do Swedes have Sámi ancestry?#

Northern Swedish genomes carry Sámi-related ancestry as a measurable component. Elsewhere in Sweden the share is small. The Sámi themselves are a distinct population with a Siberian-related layer that most Swedish genomes do not carry.

Terms used here are defined in the glossary.

Sources and further reading#

1. Günther, T. et al. (2018). Population genomics of Mesolithic Scandinavia: investigating early postglacial migration routes and high-latitude adaptation. PLOS Biology, 16, e2003703.
2. Skoglund, P. et al. (2012). Origins and genetic legacy of Neolithic farmers and hunter-gatherers in Europe. Science, 336, 466 to 469.
3. Skoglund, P. et al. (2014). Genomic diversity and admixture differs for Stone-Age Scandinavian foragers and farmers. Science, 344, 747 to 750.
4. Malmström, H. et al. (2019). The genomic ancestry of the Scandinavian Battle Axe Culture people and their relation to the broader Corded Ware horizon. Proceedings of the Royal Society B, 286, 20191528.
5. Allentoft, M. E. et al. (2015). Population genomics of Bronze Age Eurasia. Nature, 522, 167 to 172.
6. Margaryan, A. et al. (2020). Population genomics of the Viking world. Nature, 585, 390 to 396.
7. Krzewińska, M. et al. (2018). Genomic and strontium isotope variation reveal immigration patterns in a Viking Age town. Current Biology, 28, 2730 to 2738.
8. Rodríguez-Varela, R. et al. (2023). The genetic history of Scandinavia from the Roman Iron Age to the present. Cell, 186, 32 to 46.
9. Lamnidis, T. C. et al. (2018). Ancient Fennoscandian genomes reveal origin and spread of Siberian ancestry in Europe. Nature Communications, 9, 5018.
10. Humphreys, K. et al. (2011). The genetic structure of the Swedish population. PLOS ONE, 6, e22547.