In the south of Scandinavia, it’s not uncommon to see low, rounded hills appear here and there across expanses of flat farmland: These are often the remains of Viking-era burial mounds, many plundered centuries ago and plowed under by 19th-century farmers. In 2018, local officials asked the Norwegian Institute for Cultural Research to investigate the area around such a burial mound in Gjellestad, a site just north of the Swedish border. Ground-penetrating radar revealed the outlines of ten more mounds, plowed under in the last 150 years—and the ghostly outline of a wooden ship just six inches below the surface of a potato field.
The ship was likely from the Viking era and its apparent size, more than 60 feet long, would make it one of the largest yet discovered. It was the first intact Viking ship discovered in decades and declared a “hundred-year find” by archaeologists.
The Gjellestad ship also wasn’t supposed to be dug up—at least not anytime soon—but the effects of climate change and increased agriculture have forced the archaeologists’ hand. Their five-year study—the first Viking ship grave excavation of its size in more than 100 years—not only provides an unprecedented treasure trove of information on the ships and burials of the formidable ancient seafarers, but also serves as an experimental testbed for what even the tiniest artifacts can tell us.
Not buried at sea
While the image of Viking warriors laid to rest in their sleek ships is a mainstay of popular culture, the idea that the craft were set on fire or pushed out to sea as part of burial ceremonies has little archaeological evidence to support it.
Rather, around A.D. 400, hundreds of powerful Scandinavian warlords began to be buried in their longships under earthen mounds more than 20 feet high. Thousands more, presumably of lesser means, were buried in smaller boats.
Today, however, Scandinavia’s ship graves are a critically endangered species. Over the centuries, the prominent mounds were robbed or plowed away, their contents stolen or damaged. The few ships found since 1904 were simple shipwrecks or were left in bogs.
This made the Norwegian government’s 2018 decision to leave the newly discovered Gjellestad ship underground a surprise to the public, but not to archaeologists who understand sometimes leaving things in the ground is the best way to preserve them for future researchers.
A year later, however, a team of archaeologists returned to the potato field to conduct a small excavation and get a sense of how well the wooden longship was preserved. A trench cut across the center of the vessel revealed that the keel—the “spine” of the ship—was still intact, surviving for centuries in a deep, damp layer of earth. Based on tree rings from the keel and other parts of the vessel, researchers learned the Gjellestad ship was built sometime around A.D. 800.
Thanks to an agricultural ditch dug in the 1960s and increasingly hotter, drier weather due to climate change, however, parts of the ship above the keel protruded above the protective water bath that had kept the ship’s wood oxygen-free and intact for more than a thousand years.
“The keel is so deep it’s been wet the whole time,” says excavation director Christian Løchsen Rødsrud, a University of Oslo archaeologist, “but the [planking has] been dried and become wet again so many times, there’s not much left.”
What’s more, archaeologists identified an aggressive fungus present within the ship that had begun to consume any wood that remained. What started as a cursory examination quickly unfurled into a large-scale emergency excavation: the Gjellestad ship had to be dug up.
“It’s going to be like Tetris"
In the summer of 2020 researchers broke ground on a Viking ship burial for the first time since 1905. The condition of the ship forced Rødsrud and his team to get creative. The top half of the Gjellestad ship had been plowed away long ago, and much of what remained had rotted away, leaving just plank-shaped impressions in the soil.
But a key element of the ship’s construction remained: More than 1,400 rusted-covered iron rivets, each exactly where it was when it held the ship’s planks together. Every rivet is surveyed, and its exact location recorded before being excavated in a small block of surrounding soil. Over the next year, each block of soil will be CT scanned, and the rivets reassembled into a 3-D model of the ship. Ultimately, the rivets will map the curvature of the hull, creating a digital version of the ship itself.
“Imagine reconstructing a house by looking only at the nails and roof beam,” Rødsrud says. “It’s going to be like Tetris.”
Even before the digital model is complete, the researchers have uncovered critical clues about the Gjellestad ship. The 60-foot-long keel is unusually skinny for a Viking longship, and it’s missing the reinforcements required to support a mast—meaning the vessel might have been rowed, but never sailed.
More importantly, the vessel dates to the late 8th century, around time Scandinavian mariners first began to fit sails on their longships, which made them capable of both long voyages and fast, sudden attacks. This suggests that the Gjellestad ship “is from the very beginning of the Viking Age,” says Rødsrud, and could be a transitional design reflecting a period of experimentation with sails. However, “[w]e cannot conclude that the ship was not able to carry a mast before the reconstruction is made,” he adds.
Jan Bill, a curator at the Viking Ship Museum in Oslo and expert on Viking-age sailing vessels, suggests cost might have been a factor. Sails were hand-woven from wool, involving huge investments of time and labor. Perhaps the mast and sail were removed from the Gjellestad ship and reused on a later vessel. “The cost of the sail might be almost as much as the ship itself,” says Bill. “It could be they removed the mast because it was so expensive.”
Theater of the Dead
The technology researchers bring to the first Viking ship excavation in a century is also providing extraordinary insight into Scandinavian burial practices at the time. By analyzing the soil in and around the Gjellestad ship, archaeologists were able to determine that people cleared a 50-foot circle of grass and topsoil from the site before hauling the ship on shore, possibly from a nearby stream. A ditch dug around the circle would keep spectators away from the vessel in its center, while an earthen ramp or gangplank was installed on one side of the ship to facilitate the burial. At the bow of the ship was a “pool” of blue-grey clay. The effect may have resembled a theater-in- the-round, with rituals taking place on the ship over weeks or even months.
Such Viking ship burials were “more than just a static ceremony,” says Neil Price, an archaeologist at Uppsala University in Sweden who was not part of the project. “They’re an arena for interacting with the dead.”
Whoever orchestrated the burial some 1,200 years ago paid attention to the smallest details. Squares of sod were carefully cut and then re-used like bricks to build up around the burial chamber. Squashed into layers less than an inch thick over hundreds of years, the turf bricks allowed the researchers to pinpoint the time of year it was cut by the blades of grass. The long-gone warlord was laid to rest at “harvest season, when the fields are all yellow,” Rødsrud notes.
The scene has echoes in other well-known Viking ship burials like the Gokstad ship, which was built not long after Gjellestad vessel and is now on display in Oslo’s Viking Ship Museum. Researchers took over 100 soil samples from its burial mound, which was excavated in 1880 and still stands today.
By analyzing the layers of soil in and under the Gokstad mound, Rebecca Cannell, a soil expert working for the Norwegian Institute for Cultural Heritage Research, revealed other Viking ship graves were also far more than just piles of dirt. The Gokstad burial, too, was elaborately constructed, with a clay “pool” beside the ship and turf squares in alternating colors brought from nearby wetlands and stacked in specific patterns above the burial chamber. “It would have been beautiful,” Cannell says, “like a mosaic in brown and black and green.”
Ravaged by Bluetooth
When they began their work, archaeologists hoped to find out who was buried in the Gjellestad ship. Skeletons found in other ship graves belonged to both women and men; often there were multiple people interred in the mounds, with some perhaps representing retainers or enslaved people sacrificed to accompany their ruler into the afterlife. Unfortunately, the archaeologists soon realized the burial had been plundered long ago. “There’s no gold or silver left, even though I’m sure they were in there,” Rødsrud says.
But because burial mounds were important symbols representing a Viking community’s revered ancestors and were often erected next to significant settlements, presumably filled with heavily armed warriors, the theft was puzzling. How, they wondered, could tomb robbers escape undetected and unpunished? “You can’t really rob something like that in secret—it’s huge,” Price observes. “You’d not only have to dig a hole but cut through the ship’s planking.”
From disturbances in the soil around the plundered central chamber of the Gjellestad ship, the team determined that robbers cut a gaping tunnel in the mound’s west side, possibly big enough for someone to walk upright into the burial chamber.
Similar break-ins at other Viking burial mounds have been dated to 950, coinciding with the takeover of southern Norway by Harald Bluetooth. Archaeologists think the conqueror made a show of violating the graves of his rivals’ ancestors—and the Gjellestad ship burial might have been one of his targets.
Whenever they broke in, the Gjellestad robbers didn’t get everything, and what’s left hints at the rich treasure that once lay within: amber and glass beads, some covered in gold foil, a broken whetstone, a shard from a glass beaker, and fittings from a large wooden chest. Inside and outside the burial chamber, archaeologists recovered the bones of horses and oxen, suggesting a sacrifice accompanied the deceased to the afterlife. Other finds are more mysterious, like an axe head apparently wedged under the ship’s hull during the burial’s staging, either to prop it in place or as part of an unknown ritual.
Over the next year, Rødsrud’s team will continue scanning rivets and reassembling them digitally. They’ve decided not to unwrap the blocks of soil that contain the ancient fasteners: As part of a planned museum on the site, the rivets will be put back in the ground, in the exact spots where they were found. The data gathered, meanwhile, will be made available to scholars around the world to study, and hopefully reveal more about what drove the Vikings to set sail across the known world in their fearsomely efficient longships. In the meantime, the research team will continue to post their results online, and hope to soon have a digital reconstruction to “display” virtually.
“[The Gjellestad ship is] a type of ship we didn’t know before,” Rødsrud says hopefully, “and I’m sure it will tell us about seafaring in the Viking Age in a new way.”