This article is about the Norse warriors who are referred to by this name. Berserkers (or Berserks) were Norse warriors who had sworn allegiance to the sky god Odin. They worked themselves into murderous fury before a battle.

The term berserker comes from Norse "berserkr", meaning literally "bear shirt", but alluding to wearing the "clothes" of a bear, i.e. to be bear-like in rage and strength, usually in battle.

The origin of berserkers is unknown, although Tacitus mentions groups of Germanic warriors with berserk-like fury.

It appears that berserkers were religiously-inspired warbands or warrior societies . Norse sagas mention berserker gangs with twelve members where new applicants had to go through a ritualistic or real fight to be accepted. Some berserks also took names with björn or biorn in them in reference to a bear. This is likely to be the source of names such as Beowulf and Bödvar Bjarki.

Berserker bands' fearsome reputation and the sight of raging warriors charging headlong into battle surely had a demoralizing effect on the opposition. However, allies were wary of them as well because berserkers could decide to pillage a friendly village on their own and rape their women.

Snorri Sturluson mentions berserkers in the Ynglinga saga and they appear prominently in Egilssaga and The Saga of Hrólf Kraki. Many sagas describe berserkers as villains who kill, loot, and plunder indiscriminately. Erik the Red might have been a berserk.

Harald Finehair, founder of the kingdom of Norway, used shock troops of berserker warriors. Grettissaga tells that those warriors were ulfhedinn or "wolf-coats", meaning that they wore wolf skins.

Many northern kings used berserkers as part of their army of hirthmen and sometimes equivalent to a royal bodyguard. It may be that at least some of those warriors just adopted the organization or rituals of berserk warbands or used the name as a deterrent or claim of their ferocity. It is doubtful any king would have accepted a band of homicidal maniacs as his closest men.

In 1015 King Erik of Norway outlawed berserkers. Icelandic Christian law banned berserkers as heathens and sentenced them to outlawry. By the 1100s organized berserker warbands had disappeared.

Berserkers are reported to have worn bearskins in battle as the thick fur would have worked as leather armor. Bear worship was not unusual in northern Germanic areas. "Possessed" by the spirit of the bear, they might have believed that they had its strength and ferociousness and could even take on the animal's shape. In that respect, they are the basis of fantasy characters like Beorn in The Hobbit.

Warriors of the Varangian Guard (Norse warriors working for Byzantine Empire) also followed bear rituals.

Berserkers fought with crazed or drugged strength, heedless of danger. They worked themselves up into a bloodlust – berserker rage – before battles, banging their helmets with their weapons, biting their shields, and howling. They were said to be immune to pain (or even immune to weapons) in battle. In their fury they would attack their enemies but also everything else in their path, sometimes even their own people and allies.

Theories to explain berserker behavior

One explanation behind beserker rage, suggested by botanists, is that in Scandinavia, one of the main spices in alcoholic beverages was the plant bog myrtle (Gale palustris). The drawback is that it increases the hangover headache afterwards. Drinking alcoholic beverages spiced with bog myrtle the night before going to battle, might have resulted in unusually aggressive behavior.

Those who believe in the existence of spirit possession favor a theory that the berserk rage was brought on by possession by an animal spirit of either a bear or a wolf. According to this theory, berserkers were those who had cultivated an ability to allow the spirit of a bear or wolf to take over their body during a fight. This is seen as a somewhat peculiar application of animal totemism.

Proponents of the drug theory favor ergotism or the use of the fly agaric mushroom. Drunken rage would do as well. It is also possible that berserkers worked themselves into their frenzy through purely psychological processes, i.e., frenzied rituals and dances. According to Saxo Grammaticus they also drank bear or wolf blood.

A UK television programme in 2004 tested the possible use of fly agaric and alcohol by training a healthy volunteer in the use of Viking weapons, then evaluating his performance under the influence of fly agaric or alcohol compared to no influence. It was obvious that use of fly agaric or alcohol severely reduced his fighting ability, and the tentative conclusion drawn was that berserk state was achieved psychologically; otherwise berserkers would have been too easy to kill.

Going berserk – berserksgangr or berserkergang  – could also happen in a middle of daily work. It began with shivering, chattering of the teeth, and a chill in the body. The face swelled and changed its color. Next came great rage, howling, and indiscriminate brawling. When the rage quelled, the berserker was exhausted and dull of mind for up to several days. According to sagas, many enemies of berserkers exploited this stage to get rid of them.

U.S. professor Jesse L. Byock claims (in Scientific American, 1995) that berserker rage could have been a symptom of Paget's disease. Uncontrolled skull bone growth could have caused painful pressure in the head. He mentions the unattractive and large head of Egill Skallagrímsson in Egilssaga. Other possibilities are mild epilepsy and hysteria.

Today the word "berserker" applies to anyone who fights with reckless abandon and disregard to even his own life, i.e., "goes berserk".

See also: amok, Bjorn the Pale, werewolf.

External links

• Berserkergang on winterscapes.com
• Berserkergang on Viking Answer Lady