It begins with a drunken braggart and ends with a splinter in the thunder god's skull. The tale of Thor and Hrungnir is one of the oldest and most colourful combat stories of the North: a horse race all the way to Asgard, a clay giant with the heart of a mare, and a duel decided by a three-day-old child. Snorri tells it with obvious relish, and behind him stands an even older skaldic poem. Let us sit by the fire.
It all starts harmlessly enough. Odin rides out on Sleipnir, his eight-legged stallion, and meets Hrungnir, mightiest of the giants. One word leads to another, and soon they are arguing over whose horse is faster. Hrungnir swears that his stallion Gullfaxi, Golden Mane, outruns any steed in Asgard. Odin bolts, Hrungnir gives blind chase, and in his eagerness he fails to notice that he has long since crossed the borders of the gods' world. Only at the very gates of Asgard does he pull up.
The gods do what hospitality demands: they invite him in. They hand him the great drinking bowls from which Thor usually drinks, and Hrungnir empties them one after another. The wine does its work. The guest turns into a loudmouth. He roars that he will carry all of Walhall off into the world of the giants, sink Asgard, kill every god, and spare only Freyja and Sif to take them with him. Freyja is the only one who keeps pouring, while the others look on helplessly. Things have come to that.
Then Thor comes home, hammer already in hand, and wants to strike the braggart down on the spot. But Hrungnir invokes the law of hospitality and demands instead an honest duel, a holmganga, at the borderland of Grjótúnagarðar. Killing an unarmed man in the hall would win Thor little honour; an open fight is another matter. Thor agrees, and Hrungnir returns home to arm himself.
The giants fear for their strongest. From clay they knead a huge helper, Mökkurkálfi, nine leagues tall and three broad. The only heart they could find large enough was that of a mare, and even that beats up into the clay colossus's throat with fear. Hrungnir himself is all of stone: his heart is stone and three-cornered, his head is stone, and his shield is a broad slab of rock. His weapon is a hein, a mighty whetstone, which he carries slung over his shoulder. An opponent like a walking cliff.
Thor does not come alone. His servant Þjálfi, quick and cunning, runs ahead to the field and calls out to the giant that it is foolish to hold the shield before him: Thor will come up from below, through the earth. Hrungnir believes it, throws the heavy stone shield to the ground, stands on it to guard himself from beneath, and takes the whetstone in both hands.
Then Thor arrives, not from below but in full thunder from the front, and hurls Mjölnir. In the same instant Hrungnir throws his whetstone. The two weapons collide in mid-air. The whetstone shatters. Part of it falls to earth, and from that, the tale says, come all the whetstone rocks in the world. Another shard, however, drives into Thor's head and lodges there. But Mjölnir flies on and smashes Hrungnir's stone skull. The giant topples forward, and his enormous leg falls across Thor's neck. So the victor lies pinned beneath the vanquished, unable to move.
He came when but the third night was old, / and roused the Norns to a new-shaped fate.after the Prose Edda / Skáldskaparmál (public-domain translation tradition)
No god can raise the leg. Then Magni comes running, Thor's son by the giantess Járnsaxa, just three nights old and already of boundless strength. He lifts the leg aside like a twig and only regrets that he came too late; with his bare fist he would have driven the giant into the ground. Thor rejoices in his son and rewards him with the golden-maned Gullfaxi, much to Odin's displeasure, who thinks so fine a horse should have gone to the father rather than to the son of a giant woman. Meanwhile Þjálfi has slain the clay giant Mökkurkálfi without much trouble; against a real opponent the colossus with the mare's heart was worth little. Anyone curious about this younger generation will find them in Magni and Modi, the heirs of Thor.
The shard stays in his head. Thor returns home to Þrúðvangr with the stone still in his skull. They summon the sorceress Gróa, whose husband Aurvandill is far away in foreign lands. She begins her galdrar, her charm-songs, and already the stone begins to loosen. Then Thor, wanting to give her joy, tells her that he himself once carried her husband Aurvandill in a basket across the icy rivers of the North. One of his toes stuck out of the basket and froze; Thor broke it off and threw it into the sky, where it now shines as a star, Aurvandill's Toe. Aurvandill will soon come home, he says. But in her joy at this news Gróa forgets her spells entirely. The stone loosens no further and remains forever in Thor's head. That is why, Snorri concludes with a wink, one should never throw a whetstone across the floor: for then the stone stirs in Thor's skull.
The narrative appears at length in Snorri's Skáldskaparmál, the second part of the Prose Edda around 1220 to 1230, and there it draws explicitly on a far older skaldic poem, the Haustlöng of Þjóðólfr ór Hvíni from the ninth or early tenth century. The fight thus belongs to the oldest stratum of Thor tradition. Kennings such as "cleaver of Hrungnir's skull" for the hammer or "foe of Hrungnir" for Thor are firmly established in skaldic verse, which shows that the story was familiar to poets and their audiences long before Snorri.
The three-cornered "heart of Hrungnir" is today often equated with the valknut, that interlaced triangular knot found on picture stones like Stora Hammars. This is uncertain. Snorri says only that the heart was of stone and had three points; whether he meant precisely the symbol we call the valknut is stated nowhere. The name valknut itself is, moreover, a modern coinage. One should therefore not hastily lump together the three-pointed heart-shape of the tale and the knotted valknut; they are two different things, perhaps related, perhaps only coincidentally alike.
Thor · Thor at Geirröd's · Magni & Modi – Thor's sons · Thor's goats · The Norse pantheon.