[Manardariel]

"Der Nibelungenring" is actually an ancient Saga from the Rhineland. I don´t know the Opera, but the saga is a typical Hero-legend thingy. Actually it´s pretty similar to greek mythology. For exaple there´s a character that is invincible everywhere exept for one spot of his body. Anyway, like I said, it´s an ancient tale and still popular. I guess it´s posible that Tolkien knew that tale and (maybe even unintentionally) was inspired. BUT: Be carefull on one thing: Der Ring der Nibelungen isn´t talking about a ring, like as in piece of jewlery. Rather, a RING of tales is a saga of different tales that are all coneccted. In this case, they are all coneccted by the Nibelungen Family.