(Also Ragnarök, Ragnarökr, Ragnarøk)
"doom of the divine powers"
"increase of ravens"
"godsdark"
"rain of dust"
In Norse mythology, Ragnarok, also called Götterdämmerung ('twilight of the gods'), was the battle between the forces of good and evil that marks the end of the world as it had been previously known. In Viking societies, death in battle was the most desirable fate and this carried over to the worship of deities who were not everlasting or immortal. The final outcome of the last battle, including who would live and who would die, was known by the Vikings as well as the gods themselves. Every event leading up to and occurring during Ragnarok was chronicled in sagas and skaldic poetry, such as the Voluspa (Prophesy of the Seeress), the Poetic (of Elder) Edda and the Prose (or Younger) Edda written by Snorri Sturluson.
The prelude to Ragnarok included recognizable signs. First there would be three winters of war in Midgard where brother would kill brother and father would kill son. Vows would no longer carry meaning and chaos would increase throughout the world. Following that would be three winters with no summertime between them called Fimbulvetr (Fimbul, the mysterious or monstrous winter), the winter of winters. Snow would cover the world, and the land would be besieged by frost and blizzards. Skoll, the wolf would catch and devour the sun, and his brother Hati would devour the moon, and so the earth would be thrown into darkness. The stars would also disappear. Three cocks would crow: Fjalar, who would call to the giants, the golden cock Gullinkambi, who would call to the gods and a third, whose crowing would raise the dead. This would mark the beginning of the end.
Earthquakes then break all bonds and fetters, freeing the wolf Fenrir and his father, the trickster god Loki. The sea rises with the fury of Jormungand, another of Loki’s sons, who makes his way to dry land poisoning the earth and sky with his breath. His writhing loosens the moorings on the giants' ship Naglfar, which is commanded by Hymir (Hrym) and made from the nails of dead men. A second ship sets sail from Hel with Loki at the helm carries the inhabitants of the underworld. The two ships head towards the battlefield as the sky opens and the fire giants led by Surt leave Muspellheim to fight against the gods. Loki assembles his troops on the battlefield Vigrid ('battle shaker') while Surt (Surtr), with his flaming sword igniting all he passes, rides with his troops across Bifurst, the Rainbow Bridge, which collapses in flames.
Heimdall, the guardian of the bridge, is the first of the gods to see the danger approaching and he sounds the horn Gjallarhorn in warning. The gods in Asgard, roused by Heimdall, quickly hold a meeting and Odin rides to the Well of Knowledge to consult with Mimir. Yggdrasil, the world tree, groans and shakes making all the creatures of the worlds fearful. The Aesir arm themselves and Odin collects the Einherjar, the souls of fallen heroes from Valhalla. Then he, wearing a golden helmet, carrying his spear Gungnir and with Thor at his side, leads the group to the battlefield where all manner of gods, giants, dwarves, demons and elves have assembled.
Odin engages Fenrir while Thor fights Jormungand, making him unable to help his father. Surt quickly kills the swordless Freyr, and Thor bests the serpent but then its poison gradually kills the god of thunder. Tyr fights the hellhound Garm from Gnipahellir and the two slay each other. Odin is swallowed by Fenrir, and Odin’s son Vidar grasps the wolf’s jaw and rips it apart, thus killing Fenrir. Loki and Heimdall, who are age-old enemies, meet on the battlefield and kill each other.
Then, Surt flings fire in every direction which destroys the nine worlds, killing humans as well as the gods and other races. Animals and monsters die as Midgard, Asgard, Niflheim and Jotunheim blaze like furnaces until the world finally sinks into the sea.
There is no end, however. After the destruction, a new green and lush earth will rise from the waters, with fields that grow crops without having to be sewn. Animals will return. The meadow Idavoll from the destroyed Asgard will survive the destruction and a new sun, a daughter of Alfrodul the old sun, just as fair as her mother will step up to travel her mother's road in the sky.
There will be survivors among the gods. Vidar and Vali, both sons of Odin will live through the battle, as well as Modi and Magni, the sons of Thor, who will possess Mjolnir, their father’s hammer. The dead god Balder and his brother Hod will return from Hel to dwell in Odin’s former hall. They will all sit together and discuss the things that have come to pass, and in the grass at Idavoll they will find the gold pieces used by the Aesir to play draughts. Two humans, Lif and Lifthrasir, will have also survived by hiding in Hodmimir’s Holt, a small thicket in the branches of Yggdrasil, where they slept through the final battle. Upon waking, they will sustain themselves on morning dew and become the progenitors of the new human race.
According to the Prose Edda, which is not necessarily a reliable source as it wasn't penned by Snorri Sturlson until about 1200, there will remain many places to house the souls of the dead. Above Asgard there existed a second heaven called Andlang, and above that a third called Vidblain. Both Eddas state that after Ragnarok, Gimle’s hall will be the best place in heaven and Brimir will have the best things to eat and drink. The hall Sindri will house the souls of the virtuous while Nastrand ('Corpse Strand'), a hall filled with poisonous snakes facing inward that fill the hall with venom, will house the souls of murderers and oath-breakers who will be forced to painfully wade through the poison forever. Another survivor, the serpent Nihogg, will reside in Hvergelmir and will there torment the bodies of the dead.
An often neglected fact is that Ragnarok has already happened, and will happen again, an infinite number of times. Like nature, the Norse concept of mythology operated on cyclical terms; the final battle did not mean the end of all things just as the coming of winter did not signal the disappearance of summer forever.
Ragnarok does not translate literally into "twilight of the gods", contrary to what many sources say. The phrase was the result of a famous mistranslation.
Sources:
http://www.springwolf.com/wolves/nature/ragnarok.htm
http://www.pantheon.org/articles/r/ragnarok.html
http://www.pantheon.org/articles/h/heimdall.html
http://www.hurstwic.org/history/articles/mythology/myths/text/ragnarok.htm