Sigurd (Siegfried) was the greatest hero in Germanic legend, and central character of the Saga of the Volsungs. He was the foster-son of Regin, who sent him to recover a fabulous hoard of gold. Regin's father Hreidmar had first acquired this treasure, which once belonged to the dwarf Andvari. To get their hands on the gold Regin and his brother Fafnir had then killed Hreidmar, but Fafnir wanted the treasure for himself and turned into a dragon to guard it.
Regin wished to possess the treasure which his brother guarded, and to this end forged a great sword for Sigurd, but it broke the first time it was tested, and Sigurd had his father's sword reassembled and re-forged, and Gram stood every test. By cunningly stabbing the monster from underneath, Sigurd succeeded in slaying Fafnir, thus gaining both wealth and wisdom (by licking the blood of the slain dragon), since Fafnir was said to have understood the language of birds. When he realized that Regin intended to kill him for the gold, Sigurd slew him before carrying it away himself.
Sigurd then went to free the Valkyrie maiden Brunhild, who lay in a magical sleep, cast there by Odin, for daring to rise above his wishes. But Brunhilde had sworn only to marry the man who could ride through the fire that surrounded her dwelling. Gunnar wanted her, but could not perform the feat, but Sigurd in Gunnar's shape did so. Thus Brunhilde agreed to marry Gunnar.