Siggeir, in Norse mythology, the king of the Goths. Siggeir married Signy, the daughter of Volsung, a descendant of Odin who founded the Volsung line of heroes. At their wedding, Siggeir became enraged when he was unable to pull the magic sword Balmung out of the Branstock tree. It had been placed there by the god Odin himself, and only the youngest of Signy's ten brothers, Sigmund, was able to loose the sword and win it for himself. Sigmund refused to sell Balmung to Siggeir, and so the king of the Goths plotted revenge. He lured Volsung and his ten sons to Gothland by a courteous invitation to visit him and Signy. He then ambushed them, tying them all to a fallen tree in a forest, where a wolf devoured them, one each night. He prevented Signy from coming to their aid, but by her cleverness she was able to save Sigmund, the last one left alive. Brother and sister then vowed to avenge their family against Siggeir.
Unbeknownst to Sigmund, his sister disguised herself as a gypsy woman in order to seduce him and produce a pure-blooded Volsung heir who would help them carry out their revenge. The child of Sigmund and Signy was Sinfiotli. When he was grown, Sinfiotli helped Sigurd kill Siggeir. At first the two men were imprisoned by Siggeir, but with Signy's help they escaped. As told in the 'Volsunga Saga', they set fire to Siggeir's palace, burning him and his men to death. Signy then confessed to Sigmund that Sinfiotli was their son and went back into the burning palace of her cruel husband to die, her vengeance accomplished.