Who were the Jomsvikings?

According to the sagas, the Jomsvikings were a band of Norse warriors based in Jomsborg, which means ‘Jom Fortress’. It was called after its location on the island Jom, somewhere on the southern coast of the Baltic Sea in Pomerania (either modern-day Germany or Poland), described as ‘Wendland’ in Old Norse sources.


The Jomsvikings were originally from Denmark, and Jomsborg was a sort of Danish colony, which makes sense since the distance between the two is short by sea, but Vikings from all over Scandinavia and the North Sea eventually joined in.

The sagas agree that Jomsborg was the base of a fearsome Viking army, but one saga in particular – the Saga of the Jomsvikings (Jómsvíkinga saga) – depicts it as a highly selective warrior band which subscribed to a more stringent set of rules than other groups.

What did the Jomsvikings do?

The Jomsvikings of saga tradition were an elite band of mercenary warriors who fought for the king of Wendland, and later, for Danish kings. The sources agree that the Jomsvikings were on the losing side in the battle of Hjörungavágr, a naval battle which was fought when the Danes tried to invade Western Norway.

According to the Saga of the Jomsvikings, when not fighting and plundering abroad, the Jomsvikings stayed in their stronghold. Presumably they mostly spent their time with their fellow warriors, given that women were not allowed in the fortress.

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What makes the Jomsvikings different from other Vikings?

The Jomsvikings had a reputation for their rigour and exclusivity, and many applicants were rejected from their company.

Members of the Jomsvikings had to be between 18 and 50 years of age, courageous and scrupulously loyal to their fellow warriors. They were to avoid gossip and keep each other company – Jomsvikings were prohibited from bringing women into the fortress, nor could they be away for more than three nights without permission from their leader.

All spoils of war were to be divided equally between the group, and they had to promise to avenge each other as if they were brothers.

Compared to other saga descriptions of Viking armies, this group seems more disciplined than most, and their fearlessness in the face of death evokes legendary heroes from heroic epic.

What do the sagas say about the Jomsvikings?

The Saga of the Jomsvikings, written in the first half of the 13th century, is – as its name suggests – the source that gives us most information about the Jomsvikings.

However, the saga is considered hyperbolic and obviously influenced by legend and fantasy. For example, it describes the harbour in Jomsborg as having a berth for 300 ships, a fleet larger by far than even the royal fleets described elsewhere in the sagas.

Even more fantastically, at the end of the saga one of the Jomsvikings, Búi, is said to have turned into a dragon. Earlier in the saga, Búi is characterised as an ostentatious man fixated on wealth, and his transformation evokes the dragon Fáfnir of Norse legend – a greedy man who jealously hoarded his gold, which rendered him monstrous.

Although the Saga of the Jomsvikings might contain a kernel of truth, modern historians have understandably shied away from trusting it much. Instead, they have turned to more sober accounts, including the collection of kings’ sagas known as Heimskringla.

This text relates that, cAD 986, King Harald Bluetooth’s son Svein Forkbeard enlisted the Jomsvikings when he successfully rebelled against his father’s rule. A Danish army led by the Jomsvikings subsequently plundered in Norway on behalf of Svein in order to oust his father’s former ally and de facto ruler of Norway, Hakon Jarl, but the Norwegians were ultimately victorious.

Where was Jomsborg?

In the Viking Age, trading posts and seasonal markets sometimes grew into proto-urban settlements, and archaeological digs have revealed several emporia (small market towns) along the southern Baltic coast. Since the sagas do not give Jomsborg’s specific location, any one of these could theoretically be it, but the island Wolin is considered by far the most likely place.

In his Deeds of the Bishops of Hamburg (dating to the 1070s), the German cleric Adam of Bremen described a prosperous trading town at the Oder estuary named Iumne, and this place name is believed to be the same one as Old Norse Jóm. Modern-day Wolin is located at the mouth of the river Oder on the coast of what is now western Poland, close to the border to Germany.

Moreover, most of the Norse settlements seem to have been similar to Norse emporia elsewhere, where the townspeople included women and children. But excavated sources suggest that Wolin had a small, Norse elite consisting mostly of men living amongst an otherwise Slavic population, and it stands out for that reason. And although the evidence is not strong, most of these men seem to have been warriors.

A third reason is that, unlike the other settlements along the coast, Wolin was fortified with a wall, which is much more consistent with the literary representation of the Jomsvikings’ military stronghold than unfortified market towns made up of families, merchants and craftspeople.

By piecing together this evidence, scholars have made a good case for connecting Wolin with the Norse Jomsborg. On the other hand, in the Saga of the Jomsvikings, Jomsborg is more of an imagined than a real place, and some historians have even dismissed the Jomsvikings’ existence as the stuff of legends.

Who founded the Jomsvikings?

In the Saga of the Jomsvikings, a Viking named Pálnatóki gets on the wrong side of the Danish king Harald Bluetooth. Escaping the wrath of the king, he makes his way to Wendland, where the Wendish king offers him a piece of land in exchange for protecting his kingdom against other invaders.

Pálnatóki goes on to establish the Viking colony Jomsborg, and this becomes the headquarters of his followers, the Jomsvikings.

Other, more reliable, sagas attribute the foundation of Jomsborg to King Harald Bluetooth, but they don’t give any explicit reason or backstory for it. It is likely that establishing a military outpost on the Baltic coast helped the king gain a foothold in the region as he sought to capitalise on trade in the Baltic and the Rus’ (Russia and Ukraine).

What happened to the Jomsvikings?

The Norwegians thwarted the Jomsvikings’ invasion cAD 986, and according to Heimskringla, in 1043, King Magnus, the son of King Olaf Haraldsson, sacked and burned Jomsborg, conquering some of its inhabitants, while others fled.

Excavations in Wolin have so far not given any firm answers as to whether this could be true, but as the Viking Age drew to a close, kingdoms became stronger, independent warrior bands found it more difficult to operate, and Heimskringla’s version of events cannot be excluded.

Did the Jomsvikings really exist?

It is very likely that there were one or more Viking warrior bands in the late Viking Age, perhaps based in Wolin, then called Jom by the Norse.

Whether they called themselves the Jomsvikings, and subscribed to the ideals and rules outlined in the Saga of the Jomsvikings is another matter, but there is no reason to exclude it completely either. Something must have given rise to the legendary-flavoured stories about the Jomsvikings.

The Jomsvikings in Vikings: Valhalla

Frida Gustavsson as Freydis Eriksdotter, Leo Suter as Harald Sigurdsson, Sam Corlett as Leif Eriksson in Vikings: Valhalla
Frida Gustavsson as Freydis Eriksdotter, Leo Suter as Harald Sigurdsson, Sam Corlett as Leif Eriksson in season 2 Vikings: Valhalla

The Jomsvikings appear in the second season of Netflix’s Vikings: Valhalla, which follows the real-life historical figures of Harald Sigurdsson (later Harald Hardrada) and the explorer Leif Eriksson, and his semi-mythical sister Freydis Eiriksdottir as they navigate the end of the Viking Age.

The Jomsvikings of the show are still a military order, based in the hidden fortress of Jomsborg somewhere in Pomerania, but they are not mercenaries – instead they are portrayed as being dedicated to protecting the ‘old ways’ and worship of the Norse Gods in the face of Christianity’s spread.

They fulfil this mission in Vikings: Valhalla by rescuing Norse smallfolk from being slaughtered for their pagan beliefs, but their actions are quickly shown to have ulterior motives.

Those rescued are shown to be banned from holding weapons and excluded from the town of Jomsborg; they are instead forced to live in the nearby forest, where they are made to make weapons for the Jomsvikings. The order’s leader, Harekr, goes so far as to say that the Jomsvikings are ‘superior’ to other Vikings, and none are allowed to join unless they have a Jomsviking ancestor.

What of real history? The cleric Adam of Bremen claims that although Iumne was a heathen town, Christians were allowed to live there and remain true to their faith so long as they kept a low profile. This agrees with the flexibility and pragmatism that characterised many parts of the Viking world when it comes to religion.

Neither the archaeological remains nor written sources suggests that the Jomsvikings were fervently religious, or that they went about saving Norse pagans from oppressors.

The Jomsvikings allegedly fought on behalf of King Harald Bluetooth, who boasted on the Jelling runestone of having Christianised his kingdom, while his Norwegian opponent Hakon Jarl was portrayed as a strict pagan in Heimskringla. This suggests that the Jomsvikings were more pragmatic than dogmatic when it came to faith and did not see anything wrong with fighting on the Christian side.

Written sources suggest that knowing one’s ancestry was vitally important in the Viking Age, and there is an idea that certain qualities – including heroism and good or bad luck – were passed down the family line.

Given that these sources are so far removed in time and space from the Jomsvikings – if they ever existed – it is impossible to access what their idiosyncratic beliefs and views would have been, but the show’s writers draw on aspects from elsewhere in Norse culture to breathe life into the Jomsvikings as a unique group.

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Vikings: Valhalla showrunner Jeb Stuart explains why he chose ‘Valhalla’ to encapsulate his entire series on this episode of the HistoryExtra podcast


Dr Jóhanna Katrín FriðriksdóttirHistorian, author and historical consultant

Dr Jóhanna Katrín Friðriksdóttir is a medievalist, specialising in Old Norse history, literature and manuscripts. She is the author of Valkyrie: The Women of the Viking World (Bloomsbury, 2020), nominated for the Cundill History Prize