Jan Bartek – AncientPages.com – During excavations at Øvre Eiker near Oslo, Norway, archaeologists uncovered an unusually large longhouse. What sets this building apart is its impressive width: it measured 16 meters wide, with a central nave spanning 9 meters between the roof-supporting columns. This design required 9-meter-long beams to support the structure.
According to Jes Martens, an associate professor at the University of Oslo’s Museum of Cultural History, similar architectural features are typically found in buildings from the 1400s. Initially, researchers believed this longhouse dated from that period. However, carbon dating revealed that it was actually constructed much earlier—in the 200s AD—over a thousand years before their original estimate. Although archaeologists were initially skeptical about these results, additional tests confirmed the building’s ancient age.
Illustration of what the site might have looked like. Credit: Arkikon/Museum of Cultural History
“It was hard to believe. The longhouses previously found from that period were 5-7 metres wide. Such houses would have fit inside this enormous house at Sem, that’s how large it is,” Professor Martens told Science in Norway.
According to Martens, the building is also larger than any known structures from Denmark or Sweden during the same period.
The Layout of the House: A partition wall runs across the house, dividing the excavated section into two rooms. The eastern room likely had an open gable, while the western room appears to have been divided into stalls in the side aisles for housing animals. Credit: Charlotte N. Finnebråten.
“A building so exceptional must have represented something very special. It’s a visible sign of power and great wealth. Could it have been an early royal hall? It’s not unthinkable, given its central location in the landscape and abundant access to resources from both land and water,” says Professor Martens.
Was A Scandinavian Myth True?
During the 200s, the climate was relatively mild, and water levels were significantly higher than they are today. This allowed large ships to sail all the way to Sem, potentially. If a king had ruled in this region during the Iron Age—approximately 700 years before Viking Harald Fairhair, who is traditionally recognized as Norway’s first king—it could prompt historians to reconsider established timelines.
Professor Martens notes that some ancient Scandinavian texts reference kings dating back to around the time of Christ. While these accounts have often been dismissed as myths, recent findings suggest there may be some truth behind these stories.
Professor Martens presents multiple findings that lend support to the theory of a Nordic king residing at Sem. Evidence suggests that a royal seat in this location may have sought to unify southern Scandinavia into a single realm during the Roman era, potentially establishing Sem as a central hub of power.
“In Jutland and Funen in Denmark, thousands of weapons and war equipment from this time period have been found, originating from Norway and Sweden. These weapons must have been transported there by an army trying to conquer western Denmark. This army must have been organised from a specific place, and the one who organised them must have had great power and access to vast resources,” says Martens.
Previously, it was thought that pre-Viking Age Scandinavia consisted of fragmented regions ruled by local chieftains, with typical houses measuring only 5–7 meters wide. However, the building discovered at Sem stands out significantly, extending 16 meters wide and featuring a 9-meter span between its roof-bearing pillars. According to Professor Martens, constructing a roof with such a wide span would have been highly challenging—even by modern standards.
While the exact appearance of the original roof and walls remains uncertain due to limited evidence beyond pole holes, structural considerations suggest that the building required a steeply sloped roof to handle heavy winter snow loads. A slope approaching 50 degrees would be plausible for this purpose, yielding an estimated ridge height of 11–12 meters. For context, classic four-story apartment buildings in Oslo range from 12 to 16 meters high. This means that the third-century house at Sem would have been an exceptionally prominent feature in its landscape.
Roman Finds
The site’s strategic position along key maritime trade routes has facilitated extensive and long-standing exchanges with much of Europe. Archaeological evidence indicates interactions with the Roman Empire, underscoring the area’s historical significance in international trade.
Fragments of the Solberg Vase, an extraordinary Roman vase discovered in a nearby marsh in 1854. Credit: Museum of Cultural History
In a bog near the large building, an important discovery was previously made: the “Solberg Vase”. This find provides concrete proof of commercial connections between the Roman Empire and communities living along the Oslo Fjord. This artifact is notable for its intricate design and is the only Roman cameo glass vase discovered outside the Roman Empire. Its exceptional craftsmanship suggests that influential individuals likely owned it and may have served as a prestigious gift to a northern king.
The house is thought to have had a steep roof designed to allow snow to slide off easily during the winter months. The building on the right illustrates the typical size of houses constructed during that era. Credit: Arkikon/Museum of Cultural History.
“The find at Sem is spectacular,” says Hanna Geiran. She is the director general of the Directorate for Cultural Heritage, and was present during the initial investigations.
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Now archaeologists hope for funding to continue the work. So far, 21 metres of the building’s length have been uncovered, but the house likely extends further. Longhouses were typically twice to three times as long as they were wide at that time. The remaining part of the building lies under a road and a field on the other side.
“We’ve only examined half the house and have many questions. We don’t know the purpose of the various rooms and side aisles. We believe answers lie in the other part of the building, which could tell us more about what took place here,” says Martens.
Source: Science in Norway
Written by Jan Bartek – AncientPages.com Staff Writer