Beneath the earth lie the Dark Fields — Niðavellir in Völuspá, Svartálfaheimr in Snorri — where the dwarves keep their forges. The dwarves began as maggots in the flesh of the dead giant Ymir, and the gods gave them wit and shape; four of them — Norðri, Suðri, Austri, Vestri — were set to hold up the sky itself at its corners.
Everything irreplaceable in the mythology comes out of their smithies: Mjölnir, Gungnir, Draupnir, Skíðblaðnir, Sif's golden hair, Freyja's Brísingamen, the ribbon Gleipnir that binds Fenrir, and the Mead of Poetry brewed from Kvasir's blood. The gods rarely pay honestly for any of it — Loki's head-wager, coerced bindings, a stolen ring — and the cursed gold of Andvari, extorted in this realm, flows on into the tragedy of the Völsungs. Dwarves turn to stone in sunlight, and dealing with them in their darkness always carries a price.
Is Svartalfheim in the Eddas?
Yes — but only in one of them, and under two names, which is the realm's central puzzle. Svartálfaheimr, 'world of the black-elves,' occurs nowhere in the poems: the name is Snorri Sturluson's, appearing in the Prose Edda when the gods send Skírnir down to have Gleipnir made, and again when Loki goes to squeeze gold out of the dwarf Andvari. In both passages the inhabitants are, unambiguously, dwarves.
The Poetic Edda knows the underground differently: Völuspá 37 sets 'north, on Niðavellir' — the Dark Fields — a hall of gold belonging to Sindri's kin, the greatest smithing family among the dwarves. Most scholars take Svartálfaheimr and Niðavellir to be one place under two names; but no medieval source equates them, and the familiar nine-realms diagram in which one or the other fills a slot is a modern reconstruction — the sources count nine worlds but never list them.
The deeper tangle is the name itself. Are 'black-elves' dwarves? Snorri clearly thought so, since his Svartálfaheimr is peopled by dvergar; and his døkkálfar, the pitch-black 'dark-elves' set against the light-elves of Alfheim, look like the same beings again. But the eddic poems keep elves and dwarves separate and never mention black-elves at all. Scholars divide between seeing svartálfar as a genuine old synonym for dwarves and seeing the whole schema as Snorri's invention; the realm's very name may be a thirteenth-century coinage stretched over a much older darkness.
The forges under the earth
Whatever it is called, the place earns its keep. The mythology's greatest supply run begins with a prank: Loki sheared off the sleeping Sif's golden hair, and Thor's grip on his neck-bones sent him under the earth to make it good. There the sons of Ívaldi forged hair of living gold, the collapsible ship Skíðblaðnir for Freyr, and the spear Gungnir for Odin. Not content, Loki wagered his head with the dwarf Brokkr that Brokkr's brother — Eitri in Snorri, often called Sindri — could not forge three treasures finer. While the brother worked, a fly bit Brokkr at the bellows: once as the boar Gullinbursti took shape, once for the ring Draupnir, and once, drawing blood on the eyelid, as the hammer Mjölnir came out of the fire — which is why Mjölnir's handle is short. The gods judged the hammer worth any flaw; Brokkr claimed Loki's head, and Loki saved it on a quibble — the head was forfeit, but no part of the neck. Brokkr settled for sewing his lips shut.
The dwarves also solved the gods' most desperate problem: when Fenrir snapped every chain, they made Gleipnir from six impossible things — silent as ribbon, stronger than fate. The Mead of Poetry began in dwarf hands too, when Fjalar and Galar murdered wise Kvasir and brewed his blood with honey. Freyja's necklace Brísingamen is likewise dwarf-work, though the full story of its price — four smiths, four nights — survives only in the late Sörla þáttr and may not reflect the older tradition.
Andvari's gold
One transaction in this realm outlived the gods themselves. Travelling with Odin and Hœnir, Loki killed an otter that proved to be a shape-changed son of the magician Hreiðmarr, and the gods were held to a ransom: fill the skin and cover it with gold. Loki went into the world of the black-elves — Snorri's phrase — netted the dwarf Andvari, who swam a pool as a pike, and stripped him of his hoard down to a single ring, Andvaranautr, which the dwarf begged to keep. Loki took it anyway, and Andvari cursed ring and gold to be the death of every owner. The curse worked through Hreiðmarr, murdered by his son Fáfnir; through Fáfnir, who became a dragon on the hoard and died on Sigurd's sword; and on through the whole ruin of the Völsungs. The most consequential treasure in northern legend is not a god's weapon but a dwarf's revenge, minted in Svartálfaheimr.
Who are the dwarves?
The sources give them two births, and honesty keeps both. In Gylfaginning they quicken like maggots in the flesh of dead Ymir, and the gods grant them wit and human shape, housing them in the earth and in stones. Völuspá instead has the gods deliberate in council and make the dwarves from the blood of Brimir and the limbs of Bláinn — names usually taken as Ymir's — with Mótsognir foremost and Durinn second. There follows the Dvergatal, the 'tally of dwarves': dozens of names chanted down the stanzas, among them Norðri, Suðri, Austri, and Vestri, whom the sons of Borr set under the four corners of the sky-dome made from Ymir's skull. The realm below the ground literally holds the heavens up.
Sunlight is the dwarves' one recorded limit. In Alvíssmál, the dwarf Alvíss — 'All-wise' — comes to claim Thor's daughter, and Thor, for once fighting with words, keeps him answering questions until dawn slides over the hall — and the sun turns him to stone in mid-sentence. A being of the dark, caught out of his realm, becomes part of the landscape.
In the primary sources
Völuspá contributes the dwarves' creation, the Dvergatal, the golden hall of Sindri's line on Niðavellir, and the dwarves' groaning at the world's end. Gylfaginning gives the maggot origin, the four sky-bearing dwarves, and the errand into Svartálfaheimr for Gleipnir. Skáldskaparmál is the realm's true gazetteer: the forging of the six treasures, the head-wager, the Mead of Poetry, and Andvari's cursed gold, retold and expanded in Völsunga saga. Alvíssmál shows a dwarf abroad and petrified. No source describes the realm itself — no road down, no landscape but stone doors and firelight; it exists entirely as the place errands go to and treasures come from.
At Ragnarök
The dwarves fight for no one. Völuspá gives them instead one indelible image amid the catalogue of doom: as the world shakes, the dwarves groan before their doors of stone, those masters of the rock-wall — craftsmen listening to their mountains crack. Yet no realm is more present at the last battle, by proxy: Odin carries Gungnir against Fenrir, Thor meets Jörmungandr with Mjölnir, and the wolf comes to the field having spent ages bound by Gleipnir. The dwarves armed Ragnarök on both sides of the ledger. Whether their dark fields survive the fire is never said, though the poem's final vision has the dragon Níðhöggr flying up from Niðafjöll, the Dark Fells — a name so close to Niðavellir that the darkness under the world seems, at least, to persist.
Legacy
No realm has exported more to modern imagination. J.R.R. Tolkien lifted the names of his dwarves — Þorinn, Dvalinn, Fíli, Kíli, Glóinn, and Gandálfr for a certain wizard — straight from Völuspá's Dvergatal, and his subterranean smith-folk, proud and wronged and gold-bitten, are the dvergar's direct heirs. Wagner's Ring cycle turns the Andvari story, by way of its German cognates, into Alberich and the Nibelheim forges. Marvel's films render Nidavellir as a cosmic forge, keeping the old job description intact. Wherever a modern story sends heroes underground to bargain with smiths for a weapon of destiny, it is retracing the road to Svartálfaheimr.
Frequently asked questions
Is Svartalfheim the same as Niðavellir?
Probably, though no medieval text says so outright. Völuspá places a golden hall of Sindri's kin on Niðavellir, the 'Dark Fields'; Snorri's Prose Edda sends characters into Svartálfaheimr, where the inhabitants are dwarves. Scholars generally treat the two names as one underground realm seen through two sources.
Are dark-elves and dwarves the same beings?
In Snorri's usage, effectively yes: his Svartálfaheimr ('black-elf world') is populated by dwarves. But the eddic poems treat elves and dwarves as distinct and never mention black-elves, so many scholars suspect the equation — and perhaps the whole light-elf/dark-elf scheme — is Snorri's own systematization.
What was forged in Svartalfheim?
The mythology's essential kit: Mjölnir, Gungnir, the ring Draupnir, the ship Skíðblaðnir, the boar Gullinbursti, Sif's golden hair, the fetter Gleipnir, and Freyja's Brísingamen. The Mead of Poetry was also brewed by dwarves, and Andvari's cursed gold — the seed of the Völsung tragedy — was extorted there.
Do the dwarves fight at Ragnarök?
No. Their only appearance in the doom is Völuspá's image of dwarves groaning before their stone doors as the world shakes. Their handiwork, however, dominates the battlefield — Gungnir, Mjölnir, and Gleipnir all come from their forges — so the realm is present at the end in everything but persons.