A dwarf's curse, a re-forged sword and a thrust from below: how young Sigurd slew the gold-greedy dragon Fafnir, learned the language of birds from its heart-blood – and why that has nothing to do with Siegfried's “invulnerable skin”. Above all, though: how this dragon saga grows into the greatest tragedy of the North – through the valkyrie Brynhild and Gudrun's revenge, all the way to Atli, the Hun king Attila.
It all begins with a slain otter. On a journey, Odin, Loki and Hœnir kill an animal that was in truth Ótr, son of the magic-wise Hreidmar. As a fine, Hreidmar demands gold. Loki squeezes his whole hoard out of the dwarf Andvari – including the ring Andvaranaut. The dwarf curses the gold: it shall bring death to everyone who owns it.
The smith Regin raises young Sigurd and goads him into dragon-slaying – he wants the gold for himself. He forges him the sword Gram, made anew from the shards of the blade that Odin once drove into a tree trunk. On shrewd advice, Sigurd digs a pit in Fafnir's path and strikes from below as the dragon crawls over it.
Now the heart of the Norse version: Regin tells Sigurd to roast Fafnir's heart. Sigurd tests with a finger whether it is done, burns his thumb and puts it in his mouth. The moment the heart-blood touches his tongue, he understands the language of birds – and hears them warn him: Regin plans to kill him. Sigurd gets there first. Then he rides on Grani (a descendant of Odin's horse Sleipnir) and wakes the valkyrie Brynhild/Sigrdrífa, caught in fire and enchanted sleep.
The finest thing about this saga: it is not only text, it is image – centuries before the Edda manuscript was written.
From Fafnir's hoard Sigurd rides on Grani and finds, on a mountain ringed by a wall of fire, a sleeping figure in armour. It is the valkyrie Sigrdrífa – identified with Brynhild in the Völsunga saga – whom Odin had sunk into this enchanted sleep with a sleep-thorn. Sigurd cuts open the armour grown fast to her body, wakes her, and she teaches him rune-lore and wise counsel. The two swear love to each other. It could be the end of a beautiful story – but it is only the beginning of the tragedy.
Sigurd comes to the court of the Gjúkungs (in German the Burgundians/Nibelungs). Their sorceress mother Grimhild wants the shining hero for her kin and gives him a potion of forgetting. Sigurd forgets Brynhild entirely and marries Grimhild's daughter Gudrun. Worse still: Grimhild's son Gunnar now wishes to woo Brynhild himself – but cannot ride through the wall of fire. So Sigurd and Gunnar swap shapes by magic: Sigurd rides through the fire a second time, this time in Gunnar's form, and wins Brynhild for his brother-in-law. As a pledge he takes from her the ring Andvaranaut – the cursed gold, of all things.
The deceit comes out in the cruellest way. Bathing in the river, Brynhild and Gudrun quarrel over whose husband is the greater. In anger Gudrun reveals the truth: it was not Gunnar but Sigurd who rode through the flames – and as proof she shows the ring Andvaranaut. For Brynhild a world collapses: deceived, bound to the wrong man, robbed of her true beloved. Out of wounded pride and deep grief she demands Sigurd's death.
Gunnar and his brother Högni are bound to Sigurd by a blood-oath – so they incite the younger Guttorm, who has sworn no oath. They feed him a dish of wolf and snake flesh until he is wild enough, and send him to the sleeping Sigurd. Guttorm runs him through – but the dying Sigurd hurls his sword Gram after him and cuts the fleeing man in two. When Brynhild hears Gudrun's cry of lament, she first laughs aloud; then she confesses that she lied, and throws herself onto her own sword. By her wish she is burned with Sigurd on the same pyre. So ends what the sleep-thorn began.
Yet the saga runs on, for Gudrun survives. Against her will she is wedded to Atli, king of the Huns – and here myth touches world history. Atli is none other than Attila, the historical Hun king (died 453 AD), whose name lived on among the Germans as „Etzel". Out of greed for the Nibelung gold, Atli invites Gudrun's brothers Gunnar and Högni. When they will not surrender the hoard, he has them killed: Gunnar is thrown bound into a snake pit, where he plays the harp with his toes until an adder bites him in the heart; Högni's heart is cut out. Gudrun's revenge is horrific: she kills her own sons, born to Atli, serves them to the king at the feast, stabs him and sets the hall ablaze.
The same people, different names: Sigurd becomes Siegfried, Gudrun Kriemhild, Gunnar Gunther, Högni Hagen (a brother in the North, Gunther's liegeman in the Nibelungenlied), Brynhild Brünhild, Atli Etzel. The German Nibelungenlied (c. 1200) is Christian and courtly: the heroes wear knightly armour, only Etzel remains a „heathen".
The greatest difference, though, is a swapped heart. In the Norse version Gudrun avenges her brothers on her husband Atli. In the Nibelungenlied it is exactly reversed: Kriemhild avenges her murdered husband Siegfried on her own brothers – at Etzel's court, where everything ends in a bloodbath. Two cultures, one saga – and the question of where the deepest loyalty lies: with blood-kin or with one's spouse. The North chooses the kin; courtly Germany the marriage.
Sigurd is the Norse twin of the German Siegfried from the Nibelungenlied (c. 1200). Richard Wagner, too, drew above all on the Norse sources for his “Ring of the Nibelung”: Gram becomes the sword Nothung, Fafnir the dragon Fafner, Regin the dwarf Mime.
Honestly: the Norse version is the older and more mythic one – with gods, cursed gold and the language of birds. Wagner's Ring is a magnificent 19th-century re-imagining, but not a “genuine Viking source”. More of it in our post on Thor's hammer or on the runes.
Fact/myth: image and text sources show the core and spread of the saga; invulnerability is a motif of the German, not the Norse, tradition.