Here lies the foundation of how farmers became Vikings
To travel abroad, a farming community needed a surplus. They found that in iron.
Published
Inger Marie Møistad has been wandering through the forest in Geithus, southeast Norway, since September.
She has systematically walked through one and a half kilometres of forest in search of pits in the ground. A digital map of possible discovery sites shows her where to look.
Møistad works on the project Modum i vikingtid (Modum in the Viking Age). She is searching for coal pits, which are evidence of one of the Vikings' most important sources of income: iron.
Most people associate the Viking Age with raids, plundering, and the famous Norwegian Viking ships. But for farmers to become Vikings and traders, society had to have a surplus of resources.
Iron made farmers more efficient
"That surplus came from the production of iron, like here in Modum," says archaeologist Inger Karlberg, who is also part of the project.
Iron was important in three areas.
"It was used in agriculture, hunting, and for weapons," she says.
When ploughs, shovels, sleds, and wagon wheels were fitted with iron components, agriculture became more efficient.
"The plough could dig deeper, and farmers had better prospects for sowing seeds," says Karlberg.
Iron arrowheads and spears also made hunting more efficient.
Helmets and chainmail made of iron provided protection in battle. Wooden ships became sturdier with iron fittings. And more iron made swords longer and stronger.
"In the late Iron Age, swords that were held with two hands were introduced. This changed their combat techniques," says Karlberg.
Sold iron abroad
"Iron production has had an enormous impact on Scandinavian society as a whole. And a lot of Norwegian iron was exported," says Jon Vidar Sigurdsson, professor of archaeology at the University of Oslo.
At this time, Denmark was the largest wartime nation in Europe, according to Sigurdsson. However, they hardly produced any iron themselves.
"They needed a lot of iron for weapons. And Danish farmers needed iron for their tools," says Sigurdsson.
This is why a lot of Norwegian iron went south to Denmark, and possibly also further south in Europe.
"There was a great demand for iron across Europe. This made it possible for people in Norway to sell their iron to other countries," says Karlberg.
It is difficult to determine exactly how much iron was produced in Norway.
“But it was quite a lot. The large rivers in Eastern Norway were used to transport the iron out of Norway,” says Sigurdsson.
Modum's location was advantageous for trading iron. The area lies between the valleys of Hallingdal and Numedal, and not far from Hokksund. The Drammen River was up to six metres higher than it is today and served as a shipping route out into the world.
“They may have transported the iron by wagon in the summer and sled in the winter to Hokksund and further out from there,” says Karlberg.
Few excavations in Modum
Modum borders Ringerike, where many Viking graves have been found and where kings Olav the Holy and Harald Hardrada grew up.
Yet, there have been few archaeological investigations in Modum.
“Most excavations happen in areas and along roads being developed. We call these emergency excavations,” says Kalberg.
There have been no large-scale cabin developments or or other projects requiring urgent archaeological digs in Modum.
Now, a group of archaeologists and local enthusiasts have received funding from The Savings Bank Foundation DNB to learn more about the Viking Age in Modum.
“What's great about this project is that it's not the railway or road construction dictating where we dig. We can decide for ourselves where we want to look for traces of the Viking Age,” says Karlberg.
In addition to mapping coal pits, they have used ground-penetrating radar for their searches. A man with a metal detector is also searching Modum for Viking Age artefacts. So far, he has found a key, which may date back to the Viking Age.
Pine forests and red bogs
All of Modum lies on a sandy moraine – loose sand and gravel deposited during the Ice Age. It makes for light and dry soil, which is easy to dig in. In areas like this, archaeologists often find remains of settlements and graves.
And coal pits.
In Modum, there were plenty of pine forests and bog ore, forming the basis for iron production.
Iron can be found in the mountains, where it dissolves and end up in rivers, streams, and bogs.
“The ore was found in several places here in Modum. You can see the reddish sheen in streams and bogs,” says Karlberg.
To produce iron, they needed large amounts of charcoal. They dug pits in the ground and stacked firewood in them. Then they covered the pits with peat to control the flow of oxygen and lit the wood. This method ensured the wood burned slowly and turned into charcoal.
“They transported the charcoal by wagon to where the ore was,” says Karlberg.
Depressions in the ground
The archaeologists need to check every pit in the terrain. The map, which was created with laser scanning from an airplane, is accurate but has not captured all the coal pits. Some pits are also created by uprooted trees, not Vikings at work.
“I've already found 200 coal pits in this area,” says Møistad.
She points to one. It is not immediately obviour that this is a 1,000-year-old testament to iron production. It looks more like a depression in the ground.
In addition to a phone with maps and an app for registering finds, an important tool is a hollow metal rod.
She sticks the rod, called a soil auger, into the ground in the middle of the pit and pulls it up. Inside the hollow section, we see light, brown, and black soil.
“The black layer is charcoal residue. This shows that this is a charcoal pit,” says Møistad.
Sold complete and semi-finished products
“Every farm had people who could forge iron. They may have worked together when burning charcoal and extracting iron,” says Karlberg.
It appears that they made both semi-finished and complete products.
“Iron ingots weighing up to 60 kilograms have been found. These are flat iron bands bundled together and sold as semi-finished products. In addition, they made weapons, axes, and arrowheads that were exported as finished goods,” she says.
“It seems iron production was seasonal work, something farmers did when they weren't busy in the fields. Charcoal burning could easily take place in winter,” she says.
“Iron production waslikely overseen by local chieftains. They organised the work, ensured that the production met current standards, and were responsible for shipping the finished products. Orders for iron likely came through the chieftains’ extensive network. It was a well-organised system,” says Sigurdsson.
“We assume that slaves did the heavy labour,” says Sigurdsson, who provides expert advice to the Modum project.
Straight into history
Møistad pulls out her measuring tape and notes the diameter, depth, and height of the pit.
“These measurements allow us to calculate how much coal was produced in this pit,” she says.
She records the measurements and pit's coordinates in an app on her phone. And thus, this modest pit has become a part of Norwegian history.
It is only in the last 30 years that archaeologists have focused on the role of iron in the Viking Age. Written sources contain little about iron production.
“The classic picture we have of the Viking Age comes from the sagas. Snorri wasn't very interested in writing about iron production in Eastern Norway,” says Sigurdsson.
“Now we'll have the samples from the charcoal pits dated, and then we can learn more about the social and economic aspects of iron production,” says Karlberg.
Another reason why Modum is not commonly thought of in connection with the Viking Age is that there were no major chieftains there, according to Sigurdsson.
“Today, researchers on the Viking Age are more interested in daily life, such as how iron production was organised. This shifts the focus from the kings to local communities like Modum and the political and economic culture,” he says.
All the coal pits Møistad finds are automatically protected.
“We only excavate them if the land needs to be developed. Otherwise, the best conservation is to just leave the coal pist untouched,” says Møistad, who will continue mapping until the snow evens out the terrain.
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Translated by Nancy Bazilchuk
Read the Norwegian version of this article at forskning.no
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