When Frank set out to drain his field, a unique longhouse from before the Viking Age appeared
The landowners of the area where the oldest known longhouse in the Nordic region once stood risk losing fertile soil if archaeologists continue excavating.
Frank Borgen owns the field where the largest longhouse in Northern Europe from the year 200 was found. "You feel humbled when you think about the time span involved," he says.(Photo: Nina Kristiansen)
A spectacular discovery of an enormous longhouse from the 200s in Hokksund, Eastern Norway, could mean that Norwegian history needs to be rewritten.
It was a coincidence that they found it.
Graves and burnt skeletons in the neighbourhood
It all started when farmer Frank Borgen wanted to drain his field. He applied for permission in 2017.
"I've gotten on in years, so I wanted to drain the area so that it can be handed over to those who come after me in good condition," Borgen tells sciencenorway.no.
Annonse
Here on Frank Borgen's field, archaeologists dug two years ago. They found postholes from a longhouse, some small houses, and cooking pits.(Photo: Nina Kristiansen)
Permission was required, because the field is at Sem in Hokksund, an area full of ancient monuments.
The list is long: A royal estate built in 1602 by King Christian IV. The largest gold treasure in the Nordic region, a silver treasure, 20 graves from the Viking Age. A mysterious 2,000-year-old vase from the Roman Empire. A highly unusual axe from the late Iron Age.
There have also been numerous finds of coins, arrowheads, axes, jewellery, containers, and tools unearthed by both farmers and metal detectorists. In Borgen’s neighbourhood, archaeologists have uncovered graves and burnt skeletons.
It took five years from when Borgen applied for permission until archaeologists came to dig in the field. By then, ground-penetrating radar and metal detecting had been carried out. There was indeed something beneath the surface.
Enormous and ancient
The archaeologists started digging where the ground-penetrating radar had indicated.
"A longhouse of this size from the year 200 offers completely different perspectives than before,” says Jes Martens, who was the lead archaeologist on the Sem excavation.(Photo: Museum of Cultural History, University of Oslo)
"We only found a barn that was at most 200 years old. Then we discovered some cooking pits and remains of a few small houses," says Jes Martens, associate professor at the University of Oslo's Museum of Cultural History. He led the excavation.
Elsewhere, they found postholes from an old building. They weren't sure what it was. It could have been from the 17th-century royal estate or a hall from the Viking Age.
But it was enormous – 16 meteres wide.
"The only things we found in the massive house were two worn, ancient pottery shards that could have ended up there by chance," says Martens, adding:
"Still, we secured sample material, and it turned out to be a good decision."
The finds from Sem were dated three times.
"We couldn't believe that the large building was that old, so we sent in samples multiple times to be sure," says Martens.
But all the datings showed the same result.
Annonse
The longhouse is from the year 200.
The house at Sem may have looked like this, according to archaeologists. It was 16 metres wide, and the roof may have been up to 12 metres high.(Image: Arkikon / Museum of Cultural History, University of Oslo)
"The historical value is sky-high"
"We have known that a lot of power was concentrated at Sem, but now we know that it goes all the way back to the 200s," says Håvard Hoftun, archaeologist in Buskerud county municipality(Photo: Private)
Archaeologist Håvard Hoftun from Buskerud County Municipality also understands the importance of the find.
"The historical value is sky-high. A hall this large from the 3rd century is incredible," he tells sciencenorway.no.
"The history books need to be rewritten, not just for Norway, but for the entire Nordic region," says Jes Martens.
But before that can happen, more investigation is needed. What was the building used for? Was it a gigantic royal or chieftain's hall for feasts and banquets? Was it a trading post?
What about the rest of the house?
The archaeologists could see the enormous width, but not the length of the house.
Because they encountered a road. They did not have permission to dig there.
The longhouse likely continues underneath Semsveien and extends onto the other side, where there is also a field.
Here are the finds from the field at Sem. The house is marked in red with dashed orange lines. Key: pink - hearth, yellow - posthole, dashed lines - trenches, red - grave, blue - cooking pit, green - pit, excavation, and ditches.(Image: Museum of Cultural History, University of Oslo)
Now, the next step is up to the county municipality. They hope to carry out a preliminary investigation on the other field.
It will not be extensive. It involves an excavator removing the topsoil and an archaeologist digging small test pits into the past. This will take a couple of days and will not cost much, but it needs to be well planned, according to Hoftun.
"The county is very interested in making it happen, and the landowner is on board. Maybe this autumn," he says.
Has agreed
The landowner is Lene Myrvold Velle. She owns the field where the rest of the longhouse likely lies.
She followed the archaeologists' work two years ago – but only from a distance, while out for her evening walks. She has now become the main character in season two of the excavation of the longhouse at Sem.
Lene Myrvold Velle owns the field that has yet to be investigated.(Photo: Nina Kristiansen)
Not all landowners are thrilled when archaeologists arrive to dig on their fields and properties. But Velle is.
"I took over after my father and lease out the field. That's probably why I don't have the same attachment to the land as farmers who work it themselves. I've agreed to the preliminary investigation because this is just incredibly exciting," she tells sciencenorway.no.
The farm she inherited sits on historic ground. She knows more today, but when her father was growing up, there was little awareness of the value beneath the soil.
"He told me they found objects in the field while ploughing. The items were simply thrown away. They didn't think they could have any value," she says.
What happens if they find the entire house?
If the test pits in Velle's field reveal the rest of the longhouse, as the archaeologists suspect, the next question is: What happens next?
The Norwegian Directorate for Cultural Heritage has funded the work so far. But who will fund a full excavation of the longhouse remains unclear.
"It's hard to plan a large project without knowing what we'll find. All of this is still very fresh," says Hoftun from the county municipality.
"At the Museum of Cultural History, we don't have the funding to finance large excavations ourselves," says Jes Martens.
Different in Denmark
Martens is originally from Denmark and is involved in archaeological projects there. He explains that Danes have a completely different attitude towards and interest in ancient finds.
In Denmark, the state has purchased areas with important finds to preserve them for the future. Several private foundations pay for excavations.
"That's something wealthy Norwegians could learn from," says Martens.
He was also involved in preserving the trading site Kaupang in Norway, which dates back to the Viking Age.
It was not a simple process. Only after many years of negotiations did they reach a solution where the state leases the land to prevent it from being cultivated. Martens believes this is an unfortunate solution considering the site's historical and research-related significance.
"Politicians need to step up"
Beneath the road between the two fields at Sem, the house may be better preserved, since the soil has not been ploughed over the centuries.
To the left is the field that has not been investigated. In the field to the right are the traces of the longhouse.(Photo: Nina Kristiansen)
"In the first phase, we're focusing on the field on the other side of the road. But if there are further stages in the project, I'm eyeing the road with interest. It could also be worthwhile to take test samples in the gardens of the houses that now sit where the King's House and the medieval manor once stood," says Martens.
He believes Sem is something truly exceptional, with so many building remains from different historical periods.
"Ultimately, it's the politicians who need to step up. If they choose to do nothing, they're choosing to let everything disappear," says Martens.
Hoftun agrees:
"Politicians, both nationally and locally, need to get involved."
The mayor is paying attention
The highest-ranking local politician is Adrian Tollefsen.
He is the mayor of Øvre Eiker and has followed the excavations at Sem. He is proud of the municipality's long and powerful history.
Adrian Wilhelm Kjølø Tollefsen from the Conservative Party is the mayor of Øvre Eiker. The mayor is eager to see further investigations at Sem. “It makes sense to imagine that Hokksund was a trading centre where goods and services were sold or exchanged. This was the gateway in and out of the area that later became Norway,” he says.(Photo: Conservative Party)
"I was born and raised in Øvre Eiker and know our history well. So when the news from Sem started coming in, I wasn't surprised at all," says Tollefsen, adding:
"It's clear that Hokksund and Øvre Eiker were a central hub in the Middle Ages and Viking Age, and have remained significant right up to the present."
The plan for funding a future excavation is still uncertain.
"We haven't gotten that far yet, but it's in the back of our minds," says Tollefsen.
The longhouse lies beneath cultivated farmland.
"Øvre Eiker aims to preserve agricultural land. But we also agree that in a few exceptional cases, it might be necessary to make exceptions. We can't treat farmland as so sacred that it can't be dug up and moved to investigate our cultural heritage. This is entirely different from building apartment blocks," he says.
This is what it looked like during the excavation in 2023. Markers have been placed in the old postholes. A laboratory that analysed the samples from the building found some microscopic, burnt clay balls, suggesting there was an oven in the structure. On one side of the house, there may have been stalls for horses.(Photo: Museum of Cultural History)
Will we get to see the longhouse?
The large, ancient longhouse is not something people can actually see. Everything is underground. What was found were traces of holes from posts that once supported a roof that has long since disappeared.
"All we know about Sem comes from documentation from metal detecting and archaeological investigations. It doesn't offer any experiential value beyond the sources themselves," says Hoftun from the county.
So if the rest of the longhouse is found and excavated, the question is what happens next. It could remain invisible underground, or it could be made visible for locals and visitors alike.
This may have been the house of the first king in the region that would later become Norway – or at least a very powerful chieftain. He may have gathered an army and tried to conquer Denmark.
The Drammen Fjord once stood at least six metres higher. It was possible to sail into Hokksund both in the year 200 and later, during the Viking Age.(Image: Google Earth)
Pilgrimage to Eiker
Mayor Tollefsen once dreamed of building a museum.
"That was actually why I got involved in local politics. As a naive young man, I wanted to build a Viking museum in Øvre Eiker, so we could get the Hoen treasure back," he says.
Tollefsen has ambitions for the municipality as a tourist destination:
"If it turns out that Norway's first royal estate or capital was located here, we can handle the pilgrimage, no matter how many come to see what's at Sem."
Mayor Tollefsen's goal is to put together a package for tourists, with Sem as part of it. In Øvre Eiker lies the Fossesholm manor from 1540, now a museum. They also have the Nøstetangen glass museum and the Norwegian centre for motor history. Every summer, medieval days are held at Fiskum Church, also within the municipality.(Photo: Nina Kristiansen)
Agriculture or cultural heritage and tourism?
Landowner Lene Myrvold Velle is prepared to make her field available – both for excavation and whatever may come afterwards.
"Yes, I think it's the right thing to do. When the discoveries are this significant, you can't stand in the way," she says.
Landowner Frank Borgen is more sceptical. Although he is interested in history, he points out that large parts of Sem are already developed.
The railway came in 1866 and cuts across the fields. So does Semsveien. A pedestrian and cycle path is planned. There is a large industrial area right nearby. Residential homes have been built exactly where the royal estate once stood. On top of that, much of it lies beneath valuable farmland.
Borgen believes it's wrong to build on agricultural land.
"They should rather find other solutions in Øvre Eiker where they can illustrate the course of history, without taking cultivated land," he says.
It took seven years from the time he applied for drainage until permission came.
"In my case, with communication involving the county governor and the Museum of Cultural History, it's almost taken half a generation to get the permission," he says.
He received it in the autumn of 2024. The field may be drained as early as this spring.
At that point, trenches will be dug six to eight metres apart, according to Borgen.
"I might not hit any postholes, but we could very well come across something else," he says.
