E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A mythical king of Norway, whose subjects are called Nibelungers and territory the Nibelungenland. There were two contemporary kings in this realm, against whom Siegfried, Prince of the Netherlands, fought. He slew the twelve giants who formed their paladins with 700 of their chiefs, and made their country tributary (Lay iii.). The word is from nebel (darkness), and means the children of mist or darkness. (See NIBELUNGEN-LIED.)