Gram was forged by Volund and originally belonged to Sigurd's father, Sigmund, who received it in the hall of the Völsung after pulling it out of the tree Barnstokkr into which Odin had stuck it where no one else could pull it out. The sword was destroyed in battle when Sigmund struck the spear of an enemy soldier dressed in a wide brimmed hat and a black hooded cloak. Before he died, Sigmund instructed his wife to keep the pieces so that it might be reforged for their unborn son (Sigurd), whom she was carrying. The sword was eventually reforged by Regin for Sigurd's use. After it was reforged, it could cleave an anvil in twain.
In the Nibelungenlied (ca. 13th century), Siegfried says that the name of this sword is Balmung; in Richard Wagner'sRing Cycle (1848–1874), it is called Nothung. The name of the sword, changes depending on the story that you consider.
It was left by Wotan for Siegmund, but when Fricka tells Wotan to make sure Sigmund loses his battle against Hunding, Wotan uses his spear to break Nothung. However his daughter the ValkyrieBrunnhilde takes the sword fragments and gives them to Sieglinde. Sieglinde eventually gives the sword fragments to the dwarf Mime as she entrusts her son Siegfried to him. The God Wotan claims only one who knows no fear can reforge the sword, this is his grandson Siegfried. Nothung later breaks Wotan's spear, the symbol of his power, after which Wotan is no longer seen. Some sources refer to the sword as Balmus.
Gram is depicted on several of the Sigurd stones. The depiction of Sigurd slaying the dragon by striking with the sword from below is one of the iconography used to identify those Viking Age images which depict the Sigurd legend.