In Norse mythology, Ragnarök is the world-ending battle in which Valhalla’s warriors fight.
The einherjar of Valhalla are maintained for the final conflict, where they join Odin and the gods against monstrous enemies and other forces of chaos. The event includes a series of disasters, major deaths among the gods, the flooding or burning of the world, and its eventual renewal.
Ragnarök is often translated as “Fate of the Gods,” although the Old Norse word has generated discussion about its precise meaning. It is not simply one duel: it is a chain of cosmic events surrounding the gods’ final battle.
Fimbulwinter is a major precursor to Ragnarök, not its name. Ginnungagap is the primordial void in creation myths, while the Æsir–Vanir War is an earlier conflict between two groups of gods.