Remarkably Massive Viking Longhouse Discovered in Norway

While excavating near the ruins of a 17th century royal estate near the village of Sem in the Eiker district of southeastern Norway, archaeologists unearthed dozens of ancient postholes spread around the faint but unmistakable outline of a Viking longhouse. The architectural structure would have been of tremendous size. Early indications suggest it was probably constructed during the Viking Age, which in Norway lasted from approximately 800 AD to the year 1066.

Postholes Provide Clues to the Viking Longhouse’s Distinctive Architecture

Postholes were a standard feature of longhouses, regardless of when they might have been built. Heavy wooden posts were needed to support the walls and roofs of these massive construction projects and the posts had to be firmly anchored in the ground. But the placement of the postholes at the newly discovered Viking longhouse is curious and unique, since they were only set up to support the walls.

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“The proportions [of the house] are very different,” said archaeologist Christian Løchsen Rødsrud, the leader of the most recent summer excavations in Sem, in an interview with the online journal Science Norway. “In typical prehistoric buildings, the roof is supported by load-bearing posts placed inside the building. In the building at Sem, it seems that the walls support the roof. There are nine meters between the two walls. This is a large span, even in modern construction.”

Outside the outline formed by the first set of postholes, about 11 feet (3.5 meters) away, there were more postholes dug in straight lines. According to the Norwegian archaeologists, these would have supported separate roofing material that covered passageways running along the outside of the main structure. Given the distance between the outer and inner postholes, the archaeologists think the outer posts may have been slanted inward, bracing the outer walls to keep them from bowing under the weight of the structure’s roof.

An overview picture of the extraordinary house. Poles have been placed in the post holes. This is, however, only a small part of the house according to the archaeologists. (Museum of Cultural History)

With the wood used to make the walls and roof of the house long gone, there is no way to know for sure what the house looked like when it was in use and how exactly it was designed. But the one thing the archaeologists can determine with certainty is the size of the house and they know it was huge by ancient standards.

From one outer posthole line to another, the longhouse measured 52 feet (16 meters) across. As for its length, that is yet to be determined—but there is no doubt the house was much longer than it was wide.

“It’s an extraordinary building, and we haven’t excavated the whole thing,” Løchsen Rødsrud explained. He noted that the outline of the house is currently bisected by a road, and that no digging will take place in the field on the other side of the road until next year.

“I expect the house is much longer,” Løchsen Rødsrud said. “Twice or three times as long as it is wide.” If this estimate is correct, it means the house could be as much as 150 feet (45 meters) long from end to end. This would make it a true long house, by the standards of any place or time.

Excavation work documenting the postholes which are providing clues about the architecture of the supposedly Viking longhouse. (Museum of Cultural History)

The Hoen Hoard and Viking History in Southeastern Norway

The area around the newly discovered longhouse and the former royal estate in Sem has been famous since the 19th century. Or since 1834, to be more exact. That was the year that a stunned farmworker from the village of Hokkslund found a solid gold ring while digging in a bog on the plantation of his employer.

After the excited worker informed the landowner what he’d found the two of them dug down further. In the end, they recovered what would turn out to be the largest and most valuable Viking Age gold treasure ever found in Scandinavia.

The so-called Hoen Hoard, named for the owner of the farm who generously decided to split the treasure with the laborer who found it, included 5.5 lbs (2.5 kg) of golden coins and golden jewelry of different types and sizes. The hoard is believed to have been buried between 875 to 890, which coincides with the time when Viking ships were most active raiding and trading up and down the European coast.

There are approximately 50 jewelry pieces, 200 coins and more than 200 pearls and semi-precious stones in this priceless collection. While this gold could have been acquired through legitimate trading activity, it may also have been plundered from elite European homes during ninth century Viking raids. The gold and stones have been identified as coming from continental Europe and the Middle East, so there is no doubt it was not locally sourced.

The village of Hokkslund, where the Hoen Hoard was found, was a prominent port city in the Viking Age. The spot where the farmers dug up the gold is just 1.5 miles (2.5 kilometers) from the excavated 17th century royal estate at Sem, which highlights how much wealth circulated through the Eiker district of southeastern Norway between the peak of the Viking Age and the time when the country was ruled by hereditary monarchs.

Experts believe there were approximately 120 farms and about 3,000 people living in this region during the ninth century. The presence of a huge Viking longhouse and the most valuable Viking treasure ever found shows that wealthy and influential people were well-represented among that number.

There were definitely fortunes to be made in Eiker, thanks to the abundance of fertile farmland and to the ease with which large merchant ships could travel up and down the Drammen River, which had a water level that was 18 to 20 feet (five to six meters) higher 1,000 years ago than it is today. So perhaps the Hoen Hoard was imported to the region and then sold to an ultra-wealthy aristocrat or landowner by the Viking traders or raiders who’d acquired it. Or maybe such a person financed some Viking trading or raiding missions and was entitled to take possession of the most valuable items they recovered.

The Hoen treasure, which was found in 1834, is the largest treasure find from the Viking Age in Norway. (Kulturhistorisk Museum / CC BY-SA 4.0)

But Was This Really a Viking Longhouse?

At the moment, the archaeologists who found the supposed “Viking longhouse” near the royal estate in Sem are most concerned with figuring out its exact age. “We are very excited about which part of prehistoric or historical times it belongs to,” Løchsen Rødsrud said.

As of now, the house has been tentatively identified as a Viking Age construction project. This is because of its architectural style, which is consistent with other Viking fortresses that were built in Denmark in the late first millennium.

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The design of those buildings was customized to produce tall, long and wide structures, like the longhouse discovered at the Sem site. Such an approach to construction was most convenient for Viking Age farmers, since Viking longhouses were multi-purpose buildings that contained living spaces, workshops, cattle barns and crop storage areas all under one roof.

But the linking of the expansive longhouse to the Viking Age remains in question. This is because pottery shards have been found inside some of the postholes, and these ceramics were apparently manufactured several centuries earlier, during the Scandinavian Iron Age (500 BC to 800 AD).

The postholes could have been dug during the Viking Age on top of a much older settlement, which left pottery pieces littered across the landscape. But that is only one possibility. “If these shards are not random, the house is much older than the aforementioned houses from the Viking Age. In that case, it's quite a sensation,” Christian Løchsen Rødsrud stated.

To definitively discover the age of the structure, the archaeologists will have to wait for the results of radiocarbon dating tests that are currently being performed on seeds and charcoal recovered during the longhouse excavation. Once they know for sure when the house was built and by whom, they will gain some new and valuable insights into the construction practices of at least some ancient Norwegians, be they Vikings or earlier occupants of the Eiker region.

Top image: The excavation site at Sem where the large Viking Longhouse has been detected. Source: Frank Rødberg / County Municipality

By Nathan Falde