In the Middle High German Nibelungenlied, Alberich is a dwarf, who guards the treasure of the Nibelungen, but is overcome by Siegfried. News of the gold robbery and ring of power incited gods and giants alike to action. The giants Fafner and Fasolt demanded the ring in payment for building Valhalla, and carried off Freyja as a hostage. In the border, the gods, Odin, Frigg, Loki, Freyr, and Thor all search despairingly for the hidden treasure.
In Wagner's opera cycle Der Ring des Nibelungen, Alberich is the chief of the Nibelungen race of dwarfs and the main antagonist driving events. He gains the power to forge the ring after renouncing love. His brother, the smith Mime, creates the Tarnhelm for Alberich. Hagen, the murderer of the hero [Siegfried], is the son of Alberich by Grimhilde, a human woman.
Wagner's Alberich is a composite character, mostly based on Alberich from the Nibelungenlied, but also on Andvari from Norse mythology. He has been widely described, most notably by Theodor Adorno, as a negative Jewish stereotype, with his race expressed through "distorted" music and "muttering" speech; other critics, however, disagree with this assessment.