Attila and the Ring

At the end of one of the intermissions, Margaret Juntwait asked the Met audience about the connection between Verdi's Attila and the Ring. She just gave the answer, which was something about versions of the Norse myths in which Gutrune goes on to marry a barbarian named Attila. 

I might have put it differently. The Nibelungenlied was one of the sources of the Ring, and in it the heroine Kriemhild marries Attila after the murder of her husband Siegfried by her brother's vassal Hagen. Attila becomes her path to revenge, which she achieves by burning down the hall in which the visiting Burgundians are sleeping. Sound familiar?