E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Whoever possessed the Nibelungen hoard (q.v.). Thus at one time certain people of Norway were so called, but when Siegfried possessed himself of the hoard he was called King of the Nibelungers; and at the death of Siegfried, when the hoard was removed to Burgundy, the Burgundians were so called. (See NIBELUNG.)