View through the gate at Trelleborg to the other side.
View through the gate at Trelleborg to the other side. © Medieval Histories CC.

New Viking Ring Fortress Discovered

Denmark is famous for its four Viking Ring Fortresses. This spring a fifth was suddenly discovered in the eastern part of Zealand

The newly discovered ring fortress from the Viking Age is situated near Vallø at Køge Bay, 40 km south of Copenhagen. It has been dubbed the Vallø Ring Fortress.

A Viking Ring fortress is a circular fort with a strict geometrical plan. Distinctive features are their four gates facing each other and the  courtyard divided into four areas holding large houses of the “Trelleborg-Type”.

Vallø Ring Fortress in the Landscape
Vallø Ring Fortress in the landscape. © KMS

It has been known for more than 150 years that the remains of what was believed to be an early castle could be found in the field near Vallø. However, it was first when Nanna Holm, began to do a survey of the actual edifice that it dawned upon the archaeologists they might have made a breath-taking discovery.

The identification of the new ring fortress has been known among a select group of archaeologists for some months, but the owner of the land as well as the archaeologists with Søren Sindbæk in charge wished to keep silent until they were quite sure.

However, the results uncovered from a few archaeological trenches have now confirmed the precise circular form of the new fortress. First the archaeologists dug one trench and then they identified what was probably a gate a bit further on. By linking these two spots on the perfect circle construed through laser-tecnique, they were able to decide where a second gate should be: exactly opposite the first. And lo and behold, there it was explains Søren Sindbæk to

The newly found ring fortress measures 145 metres in diameter and is – as far as is known at this point – identical to the construction of the other four ring fortresses known from Denmark: Trelleborg, Aggersborg, Fyrkat and Nonnebakken. Whether or not there have been long-houses inside the courtyard is not know at this point.

The Vallø Ring Fortress has been ideally located; right at the cross-roads between the West and North and at the estuary of the small Køge River, which in the Viking Age was a navigable firth.

From excavations of the other ring fortresses it is known that they were surrounded by wide ramparts fitted with walls constructed of rows of poles supported by slanted beams. The exact construction of these may have differed somewhat from fortress to fortress. So-far details of the construction at Vallø are not known. Application for funding to excavate the newly found fortress are still in the pipeline.

Reconstruction of Fyrkat
Reconstruction of Fyrkat © OBB

So far the archaeologists have been able to determine that there must have been fighting at the fortress. At some point the gates were burnt to the ground and near the northern gate the archaeologists found charred oaken posts.

As of now the archaeologists are waiting for an exact date, which will be procured through C14 and dendrochronology. The other ring fortresses have been dated to the period between AD 975 – 980 and are believed to have been part of a defence system created by Harold Bluetooth.

During most of the 20th century it has been vigorously debated what the forts were. Military defence bastions meant to defend the Danes against an invading army of either Germans or Norwegians? Fortresses meant to subdue the local population in connection with the effort of Harold Bluetooth to “win all Denmark”? Or military stores for stocking necessary equipment and victuals in a situation where an invading army used a scorched earth tactic? Finally some scholars have believed the fortresses were meant as defendable stores for stocking victuals before outfitting  Viking-ship navies, such as were used in conquering Norway and later England. However, an enigmatic feature are the short span of time, the forts were function able before they were allowed to decay (before AD 1000).

Currently the dominant view is that the fortresses should be seen in connection with a number of other defence initiatives from the latter part of the reign of Harold Bluetooth – foremost the rebuilding of the wall at Dannevirke (AD 964 – 68), and the construction of the palisade at Jellinge ca. AD 968. It is believed that the ring-fortresses were meant to stock victuals sequestered through taxation and for use defending the realm against a German Invasion such as is believed took place in AD 974. However Danish history is rather hazy at this point and it is fervently hoped that new bits of information may be gathered from a proper excavation of Vallø.


Press release from The Danish Castle Centre

aggersborg coverAggersborg. The Viking-Age settlement and fortress
Ed. by Else Roesdahl, Søren Michael Sindbæk, Anne Pedersen and David M. Wilson
Series: Jysk Arkæologisk Selskabs Skrifter (Vol. 82)
Aarhus University Press 2014

Kongens Borge [The Fortresses of the King]Kongens Borge - Cover
Rapport over undersøgelserne 2007-2010 [Report from the investigations 2007 – 2010]
Series: Jysk Arkæologisk Selskabs Skrifter ( Vol. 76)
By Andres Siegfried Dobat with contributions from Marianne Høyem Andreasen, Peter Moe Astrup, Thomas S. Bartholin, Niels Bonde, Kirsten Christensen, Mads Christian Christensen, Renée Enevold, Jesper Frederiksen, David J. Gregory, Niels Haue, Jacob Kveiborg, Jonathan Lewis, Per Thorkild Mandrup, Simon Kjær Nielsen, Kenneth Ritchie and Terje Thun
Aarhus University Press 2013






Photo: obb