Sigurd is a legendary Norse hero referred as Siegfried in the German epic poem Nibelungenlied and as Sivard Snarensven in medieval Scandinavian ballads. All legends describe Sigurd as a great warrior who killed the dragon Fafnir with his sword Gram (in Nibelungenlied called Balmung), ate the dragon’s heart and received the gift of wisdom. After killing the dragon Sigurd saved Brunhild, a valkyrie (minor deity) who was cursed to sleep on a couch until a man would rescue and marry her. Sigurd immediately fell in love with Brunhild but Grimhild, wife of Gjuki, King of Burgundy prepared a magic potion that made Sigurd forget about Brunhild and married her daughter Kriemhild. Sigurd later captured Brunhild for his brother-in-law Gunnar with a deception, while Brunhild feeling betrayed joins Gunnar and his brother Hagen in the plot to murder Sigurd telling Hagen that he can be attacked only from the back.