Carbon-14 dating has confirmed that the circular fort discovered in September to the west of Køge, southwest of Copenhagen, is from the 900s, Politiken reports.
Søren Sindbæk, a professor of medieval archaeology at Aarhus University, made the find together with Nanna Holm, the curator at the castle research body Danmarks Borgscenter.
Holm explained to Politiken that they had decided to announce the discovery before the test results were in. “We didn’t want to sit on what we had found,” she said.
“But at the same time, our discovery was so surprising and unusual that we couldn’t help but retain a little doubt.”
Sigh of relief
Sindbæk told the newspaper it was with great relief he read the email containing the results of the carbon-dating analysis. “To get confirmed what we had claimed was true was a fantastic relief. It was a golden moment.”
The fort dates from the same century as the other four Viking forts found in Denmark.
One of the surprising features of the construction is that the landscape was changed drastically to accommodate it. There was initially not enough space for the circular structure, but a plateau was artificially built.
“Some poor people have moved tonnes and tonnes of heavy underground clay. It’s a really unusual building project that has been carried out, with the sole purpose that the fort would signify power.”
Next year the excavation of the site will continue and the fort will be dated using dendrochronology, tree-ring dating. It is hoped that this will be able to determine whether it was built before or after the reign of Harald Bluetooth (around 958 to 986).
It is thought that the fort might have been one of Harald Bluetooth’s strongholds or that it might have belonged to one of his enemies. “In any case we’ll learn something new about Danish history,” Holm said.