[crazydad]

Tolkien stole the Idea from Richard Wagners, Ring De Niebulungen.

[Tax-chick]

Wagner cribbed the plot from Germanic and Scandinavian legend. There aren’t that many plot similarities with Tolkien’s novels - just some general atmosphere.

A documentary I watched recently said that Tolkien was particularly influenced by the Finnish language and their national epic poem, the Kalevala.

[ItsForTheChildren]

"The Poetic Edda or Elder Edda is a collection of Old Norse alliterative verse poetry preserved in a 13th century Icelandic manuscript, the Codex Regius. Together with the 13th century Prose Edda, it is the primary surviving source for Germanic legend and Norse myth. One of the poems contained in it, the Völuspá, was a major source of inspiration to J.R.R. Tolkien."

http://tolkiengateway.net/wiki/Poetic_Edda