The 7 Viking Ring Forts – Trelleborg

A trelleborg or ring fort was a circular fortification built across Denmark and Sweden during the Viking age.

Similar structures have been found throughout Northern Europe, particularly in Ireland, but none have the same strict and precise geometrical design of the Scandinavian ring fortresses.

Around 974 the Danish Viking king Harald Bluetooth lost control of the Danevirke and parts of Southern Jutland to the Saxons. The entire complex of fortifications, bridges and roads which were built around 980 are presumed by some to be Harald’s work, and part of a larger defensive system.

- Advertisement -

Another theory suggests that the forts were built as boot camps for Sweyn Forkbeard’s troops prior to his invasion of England.

To date, archaeologists have uncovered 7 ring forts, with some possible sites currently under investigation that includes Rygge in Norway.

– Aggersborg

Aggersborg is the largest ring fort in Denmark, located near Aggersund and dates from 980 CE. The fort had an inner diameter of 240 metres with four main roads arranged in a cross, connecting the inner centre with the outer circular defensive ring. Archaeologists believe that Aggersborg could have housed as many as 5,000 men in 48 longhouses.

2- Borrering

Borrering, also called Vallø Borgring was a ring fort located on Zealand, southwest of Copenhagen in Denmark. The circular fort has a diameter of 145 metres and was protected by 10-metre ramparts, reinforced with a palisade of wooden stakes. Construction dates from around 970 or 980 CE during the reign of King Harald “Bluetooth” Gormsson.

3 – Borgeby Castle

The present Borgeby Castle sits on the site of an 11th-century Telleborg type fortress in Scania, southern Sweden. The fort has a diameter of 150 metres with surrounding circular earthworks and dates from the reign of King Harald Bluetooth.

4 – Fyrkat

Fyrkat dates from 980 CE and was constructed near Hobro in Northern Jutland, Denmark. The fort has an inner diameter of 120 metres, surrounded by earthworks and defensive ramparts. Fyrkat contained up to 16 longhouses that were separated into quarters by roads that met in the centre of the fort.

5 – Trelleborg, Slagelse

The Trelleborg west of Slagelse on the Danish island of Zealand is arguably the best preserved of the Viking ring fortresses.

Trelleborg is believed to have been ordered by King Harald Bluetooth in the year 980 CE as a means to command the Great Belt and its sea traffic between the islands of Zealand and Funen. Similar to the other Viking ring castles found so far, the Trelleborg at Slagelse was designed as an exact circle with two roads crossing at right angles in the geometric center, leading to four gates with two gates always opposite each other. In each of the four quarters stood four almost identical longhouses arranged in a square.

6 – Nonnebakken

Nonnebakken is a hill located in Odense, Denmark. Built during the reign of Sweyn Forkbeard around 980-1000 CE, the fort commanded passage along the route of the Odense River. Nonnebakken has an inner diameter of 120m with surrounding circular earthworks. Sadly, the archaeological remains of Nonnebakken took heavy damage during the late 19th century when a building for the Odd Fellow lodge was constructed on the site.

7 – Trelleborgen

Trelleborgen is a partially reconstructed ring fortress, located in the town of Trelleborg, Sweden. The fort was built from turf with a wooden palisade, possibly under the orders of King Harald Bluetooth in 980 CE.

Header Image Credit : Google Earth – Map data ©2021 Google

- Advertisement -
Mark Milligan
Mark Milligan
Mark Milligan is an award winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education and the BCA Medal of Honour.

Mobile Application

spot_img

Related Articles

Clusters of ancient qanats discovered in Diyala

An archaeological survey has identified three clusters of ancient qanats in the Diyala Province of Iraq.

16,800-year-old Palaeolithic dwelling found in La Garma cave

Archaeologists have discovered a 16,800-year-old Palaeolithic dwelling in the La Garma cave complex, located in the municipality of Ribamontán al Monte in Spain’s Cantabria province.

Burials found in Maya chultun

Archaeologists from the National Institute of Anthropology and History (INAH) have uncovered burials within a chultun storage chamber at the Maya city of Ek' Balam.

Archaeologists analyse medieval benefits system

Archaeologists from the University of Leicester have conducted a study in the main cemetery of the hospital of St. John the Evangelist, Cambridge, to provide new insights into the medieval benefits system.

Major archaeological discoveries in Mecklenburg-Western Pomerania

In an announcement by the State Office for Culture and Monument Preservation (LAKD), archaeologists excavating in the German state of Mecklenburg-Western Pomerania have uncovered seven Bronze Age swords, 6,000 silver coins, and two Christian reliquary containers.

Early humans hunted beavers 400,000-years-ago

Researchers suggests that early humans were hunting, skinning, and eating beavers around 400,000-years-ago.

Archaeologists find burial bundles with carved masks

A team of archaeologists from the PUCP Archaeology Program “Valley of Pachacámac” have uncovered over 70 intact burial bundles with carved masks.

Should the Elgin Marbles be returned?

The Elgin marbles are a collection of decorative marble sculptures taken from the temple of Athena (the Parthenon) on the Acropolis in Athens.