Named after bears, berserkers are stereotyped as primal line-breakers who could feel no pain and feared no weapon. But was this the reality in the Viking Age? Were berserkers bestial warriors fueled on blood lust and battle rage? Did they even exist at all?

Evidence for berserkers

The earliest reference to berserkers comes in the 9th-century skaldic poem called Haraldskvæði or Hrafnsmál, written by Thórbjorn Hornklofi to honor King Harald Fairhair of Norway. Here they are also called ulfheðnar or "wolf-skinned," referring to one of the three animals associated with berserkers, along with bears and boars. It may also refer to how berserkers wore the skins of wild animals to battle. 

Indeed, the Old Norse word berserkir literally means "bear-shirt." This description does not mention the so-called battle fury that berserkers are famed for today but instead refers to them as more of an elite unit within the army. 

This image of berserkers seems to shift as the Viking Age ends and the Christian Era begins, and descriptions begin to lean further into their animalistic side. In the twelfth century, the famous Icelandic poet Snorri Sturluson describes berserkers in Ynglinga saga: 

"His men rushed forwards without armor, were mad as dogs or wolves, bit their shield and were strong as bears or wild oxen, and killed people at a blow, but neither fire nor iron told upon them. This was called berserkergang." 

The biting of shields by berserkers is a common motif and is often taken to represent their fearlessness or even madness. This description was also the first mention of the so-called berserkergang or the berserker rage. 

In modern historiography and popular culture, this aspect of berserkers is heavily emphasized, but it is still unclear what it means or how it manifested in battle. Being untouchable by fire or iron is just as common a motif as berserkergang, but this is less focused on, despite having parallels to older texts such as Beowulf and even Islamic fakirs

Evidence of berserkers becomes more ambiguous when we look at the material culture. We have several carvings and engravings of what seem to be animal-skin-wearing warriors, which match descriptions of berserkers like the one from Snorri. Some appear to be performing some kind of ritual dance or sacrifice which may hint at the pre-battle ritual which invokes the berserkergang. 

Evidence of berserkers becomes more ambiguous when we look at the material culture. Photo: Stepan Soloveiv / Pixabay


The most ambiguous element of Viking berserkers is the berserkergang, their famous battle rage, which sees them become impervious to weapons and fear. One of the earliest theories surrounding this phenomenon comes from a Christian priest from the eighteenth century called Ödmann.
He suggested that berserkers ingested the mushroom called amanita muscaria, more commonly called 'fly agaric.' The mushroom is known to have psychoactive properties and was used by Siberian shamans. However, Ödmann was writing much later after the Viking Age and appeared to have little understanding of the effects of this mushroom, which causes sedation and depression, a long way away from the blood-fueled rage associated with berserkers. 

Ödmann may not have been far away with his plant-based hypothesis, though. Seeds from the henbane plant Hyoscyamus niger were found in a Viking grave near Fyrkat, Denmark, in 1977. Some symptoms of its consumption are similar to the berserker rage, which could suggest this was taken before battle to invoke berserkergang. However, the plant is also known to have been used for medicinal purposes, and we have no way of knowing that the buried person was a berserker.

The other prominent theory surrounding the berserker rage concerns less tangible methods. There have been some suggestions that berserkers were entering self-induced hysteria, which caused them to lose control of their consciousness and perform things that seemed impossible to humans (for example, as stated in Anatoly Liberman's 2005 Berserks in History and Legend). This hysteria may have been initiated through a ritual performed before battle and could have included acts such as the famous shield-biting and animalistic howling.

Jonathon Shay makes a similar but distinct suggestion in his book Achilles in Vietnam. Shay connects the berserker rage of Viking soldiers with the hyperarousal of posttraumatic stress disorder. He writes: 

"If a soldier survives the berserk state, it imparts emotional deadness and vulnerability to explosive rage to his psychology and permanent hyperarousal to his physiology — hallmarks of posttraumatic stress disorder in combat veterans. My clinical experience with Vietnam combat veterans prompts me to place the berserk state at the heart of their most severe psychological and psychophysiological injuries". 

Similar suggestions have been made that the berserker rage was a form of epilepsy or a mental illness other than PTSD.

Ultimately, we have little concrete information about berserkers, as with many things in the Viking Age. Whilst we can say that they at least existed, we cannot evidence their modern reputation of entering a blood-hungry state, and there is nothing to say that they weren't just elite warriors who wore animal skins. The ambiguity of the berserkergang makes it difficult to say whether such a thing even occurred, much less how they entered the state of berserker rage.

Whatever the reality of Viking berserkers, they were evidently unpalatable for Christian society. As Scandinavia became more Christianized, berserkers became outlawed, and by the 12th century CE, berserkers disappeared from society altogether. 

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