Gibichung

The people of King Gibich who live by the Rhine. They are ruled by his son Gunther. They also include Gibich's daughter Gutrune and the half-Nibelung Hagen, illegitimate son of his wife Queen Grimhilde.

Gunther and Gutrune, on the advice of Hagen, decide to marry Brünnhilde  and Siegfried. The Wälsung  is given a love potion and falls in love for Gutrune. He agrees to bring Brunnhilde for Gunther in exchange for marrying Gutrune and swears blood-brotherhood with Gunther. When Siegfried returns ahead of Gunther and Brunnhilda he goes into Gibichung Hall with Gutrune and Hagen calls the Gibichung Vassals to the Hall for the wedding of Gunther. However Brunnhilda claims Siegfried has been with her, which he can't remember due to the love potion. Hagen, Brunnhilda and Gunther plot the death of Siegfried, Hagen desiring the ring on the prompting of his father Alberich.

While hunting Hagen gives Siegfried a potion that restores his memories then slays him with a spear in the back. At Gibichung Hall he and Gunther fight over the ring and Hagen kills his half-brother. Gutrune dies of grief. Brunnhilda orders a funeral pyre for Siegfried which burns out Gibichung Hall and throws herself into it. The Rhine overflows and the Rhinemaidens take the ring, drowning Hagen as he tries to take it.