When I was young, I loved Wagner, but was always unhappy that he mixed up German mythology.
Looking at the recent PBS special on the architecture of Ludwig II, I realized that Wagner was writing in German, but not about "Germans".
In the beginning, the gold of the Rhine, guarded by the Rhine Maidens was the flax/linen grown on the flood plain below the Rhine. Dwarfs, gods, giants, and men could steal, build cities, become monsters, and die, but in end, the greatest wealth in Europe would come from the flax/linen grown on the flood plain below the Rhine. Skill developed in spinning that linen, brought more wealth when applied to wool. The Rhine Gold made Flanders the richest and most industrialized people of Europe, regardless of who ruled them.
Centuries later Harrlem was still a rich city based on its skill for bleaching linen.