Danish Viking-Age Ring Fortresses
The five Viking-Age Ring Fortresses were introduced on the UNESCO World Heritage list in September 2023
It was a major relief to Danish archaeologists, historians, museum directors, and representatives of the Danish Ministry for Culture and Palaces when the five Viking ring fortresses were accepted in Riyadh at UNESCO’s World Heritage Congress on 17 September 2023. Earlier a joint-Nordic application including ring fortresses in Scandinavia had not been accepted (2014), and the renewed application included the five Danish ring fortresses only, with the possibility of later extending the list. See also https://whc.unesco.org/en/list/1660
The five ring fortresses were constructed in a fairly short period between 970 and 980 CE, during the reign of Harald ‘Bluetooth’ Gormsson and his son, Sweyn Forkbeard Haraldsson, who drove his father from the throne in 986. King Sweyn abandoned further construction and maintenance after he had secured the kingdom. The only ring fortress that was used later, also by Sweyn Forkbeard, was Aggersborg where raids on England were prepared on several occasions, also as late as under King Canute IV at the end of the 11th century CE.
The Jelling Dynasty
Harald was the son of Gorm and Thyra, the first king and queen of the whole of Denmark, based at Jelling in central Jutland — at least, this is what Harald claimed on the big Jelling Stone, the largest rune inscription found in Denmark. What is today known as ‘Denmark’ was ruled up to now by a number of strong local kings over a couple of centuries, mainly chieftains with their own armies until around 950 CE. Most of the strongholds were situated in areas with trade and easy access to the sea. The alliance between Gorm, who reigned over a large part of Jutland, the peninsula that makes up the main part of the country today, and Thyra, the queen of a major part of the southern part, stretching southwards to what is today north of Hamburg in Germany. She is commemorated on a number of runestones in the area, a clear indication of the power she wielded, and no-one else has been commemorated on so many runestones. She is also known as the first ruler to establish the large rampart across the southern part of the peninsula called ‘Danevirke’ to protect against invasions from the south, mainly from the Wends, a Slavic group inhabiting what is today north-eastern Germany, and often a threat to trade in southern Denmark, mainly through the large trading centre at Hedeby.
Harald Bluetooth had the runestone carved to commemorate his parents, and it is notable that both are mentioned on the stone and mainly to manifest his own power over the newly united country. There is a smaller stone with King Gorm’s tribute to his wife, Queen Thyra. The two rune stones have been on the World Heritage List since 1994 together with the large complex including the two large tombs, attributed to Thyra and to Gorm and fortified by Harald. Harald’s large stone is remarkable for a number of things, mainly that it is first time we find the name for the country cut in stone, ‘tanmaurk’, Denmark, and for the large carved image on the other side of the crucified Christ, following Harald’s claim that he christened Denmark and Norway (‘nuruiak’). A copy of the picture of Christ is today found inside every single Danish passport.
Harald may well have converted the Danes to Christianity, as he claims on the stone, although many have noted the strong similarity between the depiction of Christ on the cross and the “hanging” of Odin on the Yggdrasil tree, from the account in Rúnatal of him hanged from a tree and pierced by a spear. It would in any case have been impossible to convert any Viking to the suffering Christ as depicted in Baroque sculpture. In early Nordic Christianity you will always see a depiction of the conquering Christ. I should perhaps also add that the present royal family can trace their roots back to Gorm and Thyra.
Harald became king in around 960 CE, and immediately set about securing his hold on the entire country. He fortified ‘Aros’ around 970 CE — where the city of Århus grew up — on the east coast of Jutland and built a fortification around his parents’ tombs. He needed to have both the economic and military hold on power, and there are clear indications that he also raided strongholds, including tombs of former local chieftains, both on the island of Fyn (Funen) and on Sjælland (Zealand). This is probably part of what led him to build a network of military strongholds throughout the country.
Harald’s Ring Fortresses
The five ring fortresses are all strategically placed — Aggersborg in the north to secure the trade and traffic on the Limfjord between the North Sea to the west and Kattegat to the east, including gathering forces to go west to raid England; Fyrkat in the central eastern part of Jutland to secure against raids from Norway or Sweden; Nonnebakkken (‘nun hill’) in the centre of Funen to pacify the Funen local chieftains (one of whose large rich tomb was raided by Harald, about thirty kilometres from ‘nun hill’); and the same in Trelleborg on the western side of Zealand, while Borgring (‘fort ring’) is situated on the eastern side of the island, placed on the cross road of several major trade routes, to protect against raids and to secure trade from the old royal seat of Lejre, close to modern-day Roskilde. It is almost certain that there was an alliance with Lejre although the fortress was never finished.
The ring fortresses were built as circular, fortified entities with large longhouses for troops (see reconstruction on lead photo), all of them placed symmetrically inside the circle in four parts, each with between 48 (Aggersborg) or 16 houses (most of the fortresses). The circles are mathematically laid out, in perfect circles, all with ramparts, a wall of timber and four gated entrances, each at a cardinal point. In most of them, markings have been established in the ground to indicate the position of the large timber beams carrying the roofs. The only ring fortress in Denmark that is not immediately accessible is Nonnebakken in Odense, as it is today mainly covered by mediaeval and modern houses, but part of the rampart is still visible and can be visited.
It would have been a major undertaking to build the fortresses and the response from locals, especially local chieftains, must have been fierce, but the fortresses were built and the coherence of the united country probably ensured — had it not been for the christening of the population.
As mentioned above, the fortresses were only functioning for a period of between ten and twenty-five years, mainly because Sweyn Forkbeard did not support them after about ten years on the throne although Aggersborg remained in use until the end of the 11th century CE, mainly to organise the large armies to send to England, including Sweyn’s raids.
Securing the heritage of a united country
There will always be discussions about Sweyn’s rebellion against his father — some see it as a return to pagan life, Viking life, honouring the old gods instead of the newly introduced Christianity. There are several sources, mainly from German bishops, that claim Sweyn persecuted Christians.
This hardly fits with his building of several churches and sending English priests and bishops to Denmark, but definitely with his sacking of the German bishops. He is seen as a typical Viking king, especially for his invasion of England and his victory over the Norwegian king, Olav Tryggvason, in 1000 CE at the Battle of Svolder.
Olav I’s story is also that of a spectacular Viking king who, like Harald, tried to turn his people to Christianity. He was first married to Gyda, the sister of the king of Dublin before sailing to Norway, now as king of Dublin, to claim the Norwegian kingship. As a child he had been enslaved by Estonian Vikings when his mother tried to flee to King Vladimir in Gardarike (modern-day Kiev) from rival Norwegian chieftains and later, after having been freed and working for King Vladimir in Novgorod, he left to raid the southern coast of the Baltic Sea, marrying the queen of Wendland (his Irish queen had died), striking an alliance with Emperor Otto II, thus becoming a part of the Emperor’s attack on Harald Bluetooth. They were stopped at Danevirke, Queen Thyra’s formidable fortification at her son Harald’s southern border. When the queen of Wendland died a couple of years later, Olav went raiding — Friesland and the Hebrides — until a seer on the Scilly Islands persuaded him to become a Christian and he was baptised by Saint Ælfheah of Canterbury in 994 CE. One could perhaps suggest that Olav’s attack in alliance with Emperor Otto was what prompted Harald Bluetooth to seek some form of peace with the empire by becoming a Christian — and it was the Emperor’s bishops who sent priests to Harald and baptised him.
Olav I chose Trondheim as his royal seat and began the conversion of the Norwegians to Christianity. It has been suggested that he dreamed of converting all of Scandinavia. Olav I had several baptised, not always voluntarily, among them Leif Ericsson of later fame when he settled in Greenland, also bringing a priest with him, founding a Christian community on Greenland’s east coast. Olav I also converted the people of the Orkney Islands, then a part of Norway. A large part of the Vikings who fled from Norway during Olav’s reign settled in Iceland, where they adopted Christianity as the country’s religion at the Althing in the year 1000 CE — without meddling in what people did at home. A pragmatism that Olav I should have practised instead of torturing and forcing people.
Sweyn Forkbeard became increasingly worried about Olav I’s intentions when he married Sweyn’s sister Tyra, who had fled, against her brother’s will, from Wendland where she had been married to the heathen king, Burislaw — something which also shattered Sweyn’s alliance with the Wends. Olav I finally died in the Battle of Svolder in 1000 CE when he was attacked by a joint force of the Danish and Swedish kings and Olav’s enemies from Norway. His battleship, Ormrinn Langi (the long serpent) was surrounded and he threw himself into the sea — stories developed afterwards about his suicide or possible escape.
The victors from the Battle of Svolder went on to divide Norway between them, and there was a general backlash against Christianity. Sweyn Forkbeard went on to recruit bishops and priests from England instead of the German ecclesiastics — and thus received a fair amount of hostility from the German bishops. He invaded England in 1003–1004 CE, eventually paving the way for his son Canute to become king of England, Denmark, Norway, parts of Sweden, Pomerania, and Schleswig. Sweyn died in Gainsborough in 1014 and his embalmed body was returned to Denmark to be buried in one of his churches, according to tradition in Roskilde, today a cathedral and burial place for Danish kings and queens ever since, and also on the World Heritage list since 1995. Harald’s grave was never found.
The five ring fortresses in Denmark are part of the national heritage, but there are more ring fortresses in the Scandinavian countries, a couple of them probably also from Harald’s time. The Swedish Trelleborg in south-western Scania is one of them, although not fully excavated, again as parts of it are underneath houses and roads. It does, though, present a formidable example of a timber fortification of the quarter of the ramparts still visible. A little north of Trelleborg is Borgeby, the second ring fortress in western Scania, another of King Harald’s ring fortresses, this time to secure the naval traffic through and fishing in the narrow sound between Scania and Zealand, one of the major thoroughfares and herring fishing grounds. Borgeby was found in the early 1990s and has since 1998 been recognised as one of the series of fortresses founded by King Harald. There might be more to be identified in the future and so far there could be two more, one in western Scania, further north of the two existing, close to Helsingborg, and one in south-eastern Norway in Rygge. Time will tell — and the list of Viking-Age Ring Fortresses on the World Heritage List may well need to be expanded.
