BERSERKERS . The Old Norse term berserkr was used to identify certain fierce warriors with animal characteristics. According to Old Norse literature, particularly the later sagas, berserkers howled like animals in battle and bit their shields. They felt no blows and had unnatural or supernatural strength, which gave way to languor after battle. The earliest attestation of the term, however, which occurs in the poem Haraldskvæði (attributed to two different poets), presents berserks as the shock troops of King Harald Fairhair at the Battle of Hafrsfjörðr (end of ninth century):
8. They [the warships] were laden with men and with white shields with western spears and Welsh [French] swords: berserks wailed, battle had begun for them, ulfheðnar ["wolf skins"] howled, irons shook. 20. About the gear [service?] of berserks I want to ask, tasters of carrion-sea [blood], how it is for the ones who go into the army, battle-brave men. 21. They are called ulfheð-nar who in battle bear bloodied shields; they redden spears when they come to battle: there they work in common; among champions alone I think would conceal himself The wise king, Among those who hack at shields.
In this tradition, at least, it is clear that there was little difference between berserkers and ulfheðnar. For this reason, many scholars understand the term berserkr as "bear-shirt," and they take both terms to refer to shape-changing in the manner of werewolves and man-bears, or perhaps to animal cloaks the warriors may have worn. Others, however, have ignored this passage and argued that the word berserkr means "bare-shirted" and refers to the berserkers' lack of armor. Explanations of the berserksgangr ("going berserk") include self-induced or group ecstasy, psychosis, or lycanthropy.
In Norse mythology berserkers are associated primarily with the god Óðinn. In his Ynglingasaga —a euhemerized account of the origin of the royal line of the Ynglingar that constitutes the first saga in his famous Heimskringla (c. 1230)—the Icelandic mythographer Snorri Sturluson gives an explicit description of the berserksgangr and attributes it specifically to Óðinn warriors (chap. 6). Óðinn also is master of the einherjar, dead warriors who inhabit Valhǫll, spending their days in battle, their evenings in feasting and drinking.
The religious complex suggested by these and other data is that of an ecstatic warrior cult of Óðinn, whose name, coming from the Proto-Germanic term *woþanaz, appears to mean "leader of the possessed." This cult probably involved strict rules of initiation, similar perhaps to those attributed by Tacitus to the Chatti (Germania 30). Óðinn's association with the einherjar may also imply worship of the dead within this cult. Its central moment, however, was presumably some form of religious ecstasy.
Iconographic evidence for this cult includes cast-bronze dies from Torslunda, Sweden, which show dancing warriors with theriomorphic features.
Fredrik Grøn's Berserksgangens vesen og arsaksforhold (Trondheim, Norway, 1929) treats the phenomenology of the berserks-gangr. Hans Kuhn's "Kämpen und Berserkir," originally published in 1968 and reprinted in his Kleine Schriften, vol. 2 (Berlin, 1971), pp. 521–531, emphasizes possible Roman influence, especially gladiator traditions. In Kultische Geheimbünde der Germanen, vol. 1 (Frankfurt am Main, Germany, 1934), Otto Höfler has offered the fullest treatment of the relationship between berserkers and the Óðinn cult, Männerbünde, and worship of the dead, arguing the existence of a mystery cult that left traces in later folklore phenomena such as the Wild Hunt. Chapter 6, "Images of the Animal Guardians," in Stephen O. Glosceki's Shamanism in Old English Poetry (New York and London, 1989) relates berserkers and the iconographic evidence for the Germanic warrior cult to shamanism and animism. Kris Kershaw, The One-Eyed God: Odin and the (Indo-) Germanic Männerbünde (Washington, D.C., 2000), adduces the Indo-European evidence.
John Lindow (1987 and 2005)