How was Buri revealed in Niflheim?
Audumla the cow licked Buri out of a block of salt, and he went on to be the ancestor of the Aesir gods of Norse mythology.
Was Niflheim also the realm of Hel?
Niflheim wasn’t originally associated with Hel, the land of the dead, but eventually the goddess Hel established her realm there.
One of the Nine Realms in Norse mythology, Niflheim was a world of elemental ice and cold. Though seldom mentioned in Norse lore, Niflheim occupied a place of enormous cosmic significance: it was Niflheim that brought forth Ymir, the first giant, and Buri, the first of the Aesir gods, Buri. In time, Niflheim became synonymous with Hel, the world of the dead, ruled by the goddess of the same name.
The name “Niflheim” was derived from the Norse words nifl and heimr, meaning “mist” and “home,” respectively. Translated literally, the name meant “home of the mist.”
Niflheim and the Norse Creation Myth
At the beginning of time in Norse thought, the glacial world of Niflheim stood at one end of the empty vacuum known as Ginnungagap, the “Yawning Void.” As the eons passed, the ices of Niflheim and the flames of Muspelheim encroached on Ginnungagap, meeting somewhere in the middle. When the heat of Muspelheim melted Niflheim's frosts, the vapors coalesced into Ymir, the first giant. The thawing ice also revealed Audumla, a sacred cow who nursed Ymir and fed on the salty blocks of ice.
After some time, Audumla’s insatiable ice-licking uncovered Buri, the first of the Aesir deities and the grandfather of Odin. In his 13th century Gylfaginning, Icelandic scholar Snorri Sturluson recounted Audumla’s role in the creation myth:
‘She licked the ice-blocks, which were salty; and the first day that she licked the blocks, there came forth from the blocks in the evening a man's hair; the second day, a man's head; the third day the whole man was there. He is named Búri: he was fair of feature, great and mighty. He begat a son called Borr, who wedded the woman named Bestla, daughter of Bölthorn the giant; and they had three sons: one was Odin, the second Vili, the third Vé.’
Buri and his sons eventually slew Ymir, for the giant had become a cruel and greedy monster. After dismembering his body, they filled the emptiness of Ginnungagap with his parts, using them to create the earth, sea, and sky.
Niflheim and Niflhel
The Gylfaginning also explained how Odin came to appoint Hel as the ruler of Niflheim. His account began with a discussion of Loki and the monstrous children he sired with the giantess Angrboda. These children—Fenrir, the giant wolf, and Jörmungandr, the Midgard Serpent— were threats to both the gods and Asgard itself. When Odin learned of Loki’s children, he traveled to Jotunheim to expel them before they became too powerful. It was during this expulsion that Odin cast Hel into Niflheim to rule over the dead:
Hel he cast into Niflheim, and gave to her power over nine worlds, to apportion all abodes among those that were sent to her: that is, men dead of sickness or of old age. She has great possessions there; her walls are exceeding high and her gates great.
Niflheim has been reimagined in Marvel Comics and the Marvel Cinematic Universe, as well as in God of War video game series. In the former, Niflheim was again a world of ice and mist. In the film Thor: Ragnarok (2017), Niflheim was the site of Hela’s banishment. The evil goddess returned from Niflheim following Odin's death, and began wreaking havoc on Asgard.
Niflheim was also featured in God of War (2018). However, this version of the world was hardly the glacial realm established in Norse mythology.