Muspelheim is the realm of fire in Norse cosmology, one of the two primordial worlds present at the very beginning of things, and it plays a role at both the creation and the destruction of the cosmos. In the Eddic account of origins, before the gods and before the ordered worlds, there existed only the fiery, glowing region of Muspelheim in the south and the frozen, misty Niflheim in the north, separated by the yawning void of Ginnungagap. Where the heat of the one met the ice of the other, the ice melted and quickened into the first living being, the giant Ymir, from whose body the world would be made, so that all creation begins from the meeting of fire and cold.
Muspelheim is guarded at its border by the fire-giant Surtr, sword in hand, and it is home to the "sons of Muspell," fiery beings who play no part in the ordinary dealings of gods and men but are held in reserve for the end. At Ragnarok they will ride out, Bifrost will shatter beneath them, and Surtr will fling fire across the nine worlds and burn them. Muspelheim thus frames the Norse cosmos: the fire whose warmth helped kindle the first life is the same fire that is destined, at the last, to consume the world.