The operas were about chief god named Wotan (=Woden=Odin, pronounced Votan.)  Wotan got his power by breaking off a branch from the World Ash Tree, called Yggdrasi, not named in this opera.   He was forced to give up eye, because he drank from a spring beneath the tree, before breaking off the branch; though, strangely, he did not have the power to grow it back.   The tree was the tree of life, that linked the various realms of existence, including the realm of the gods, and the lower realm of Nibelheim, home of the Nibelungs, technically children of the mist, a race of dwarves.  Wotan fashioned the branch into a spear, upon which he wrote the Law in the form of runes, as he made treaties and became more powerful.  However, by cutting the branch, he weakened the tree and set the wheels in motion for his eventual doom.

Crow's were Wotan's eyes and ears and messengers in the world of men. The presence of these birds always implied that he was watching, and they would always tattle to him about the progress of his many schemes.

Wagner gave the opera a specifically German bent with the creation of the Rhine Daughters, who were the guardians of the sacred gold, which had potential powers separate and vaster than those of Wotan.  One who could steal the gold would be able to transform it into a fabled Ring of power.  To fashion the Ring, the bearer of the gold had only to renounce love, which was not difficult in these operas, since love for most of the characters was quite shallow.

Normally, Asgard was the realm of the gods, and Wotan's fortress, Valhalla, was a mighty hall in Asgard, but Wagner's modified mythology made no reference to Asgard.  Valhalla was only accessible via a rainbow bridge.  Wotan had Valhalla constructed to his specifications by the Giants.  It was hard to deduce exactly when, since the timeline of the gods was different than that of human beings.  Though the gods were not truly immortal, they were effectively immortal.

In the opera, Wotan was married to Fricka, the guardian of the sanctity of marriage.  This was a strange paring, since Wotan was absolutely not monogamous, being the father of, or at least being related to, endless characters in the opera.  Due to treaties and self-limiting powers, Wotan was not able to do all the things he would really like, so he was often forced to cheat by empowering or tricking others into doing his dirty work.

Wotan's right-hand man and advisor was a demigod named Loge (=Loki.)  Loge's advice came with a price, especially since it involved a lot of trickery and hidden agendas.  Loge was the demigod of fire, who set forth a process of transformation, along with an ultimate penalty of destruction. Consumed by envy, true to his demigod status, Loge plotted for the eventually fall of the gods.