The Two Brothers
Caldwell (the editor of the parallel text edition) said the plot was taken from a Celtic variant of the widespread "Die Zwei Brüder" type story, that is, it was a cognate of "The Two Brothers" from the "Grimms' Fairy Tales"). Though this may lead one to believe Caldwell subscribed somewhat to the Germanic/Teutonic origins view, Van Duzee assures us that his thesis was that "Eger and Grime"'s plot "derived from purely Celtic sources (not Celtic and Teutonic)".