The narration states that the Wizard “built the Emerald City and united the Munchkins, Gillikins, Quadlings and Winkies into one people” (191). In The Wonderful Wizard of Oz, the Wizard does claim he built the Emerald City and he does pretend to rule Oz, but in fact his power does not extend beyond the capital city. Dorothy, the Scarecrow, the Tin Woodman, and the Cowardly Lion are responsible for unifying the people into a stable federation, and later Ozma and Glinda are too (and maybe Jinjur, kind of). While Dorothy eliminated the Wicked Witches, the Wizard was hiding in his throne room. Though a powerful political figure stealing the credit from those who did the work is true to life. (If a history says a king built a city, remember that he didn’t—laborers did.)
I did not mention it in that post, but the backstory Glinda and Mombi furnish in The Marvelous Land of Oz contradicts the backstory in The Wonderful Wizard of Oz. It contradicts the backstory the Wizard and Ozma provide in Dorothy and the Wizard in Oz even more. In The Marvelous Land of Oz, the Emerald City predates the Wizard’s arrival. The Scarecrow is clear that Pastoria, the ruler who preceded the Wizard, specifically ruled the Emerald City: “The former King of this City, who was named Pastoria, lost the crown to the Wonderful Wizard” (185–186). In this book, Mombi also states that the Wizard did, in fact, know some real magic, when he clearly does not either in the original novel or in Dorothy and the Wizard in Oz: “He taught me all the magical tricks he knew. Some were good tricks, and some were only frauds” (270). If some were frauds, then some were genuine magic. In The Emerald City of Oz and later, Baum portrays the Wizard as learning real spells from Glinda so that he finally ends up as a real wizard, further complicating whatever his magical powers are.
Glinda states that the Wizard stole the throne from Pastoria and abducted Ozma: “[W]here she is I have tried in vain to discover. For the Wizard of Oz, when he stole the throne from Ozma’s father, hid the girl in some secret place; and by means of a magical trick with which I am not familiar he also managed to prevent her being discovered—even by so experienced a Sorceress as myself” (241). Mombi, imprisoned and under threat of death, later confirms this: “The Wizard brought me the girl Ozma, who was then no more than a baby, and begged me to conceal the child” (269). Mombi also repeats the point, as if to leave no doubt: “the child brought to me by the Wizard who stole her father’s throne. That is the rightful ruler of the Emerald City!” (270). Based on this, and certainly the Wizard’s violence and unflappable ego in Dorothy and the Wizard in Oz, the Wizard was a conniving man who conspired with Mombi to unjustly maneuver himself into power over the capital city.
This has almost nothing to do with the backstory Ozma and the Wizard provide in Dorothy and the Wizard in Oz. (Though in every book so far, Ozma’s gender transition is mentioned and consistent.) During her first meeting with him, Ozma tells the Wizard, “Many years before you came here this Land was united under one Ruler, as it is now, and the Ruler’s name was always ‘Oz’, which means in our language ‘Great and Good’; or, if the Ruler happened to a woman, her name was always ‘Ozma’” (194). This implies there is an indigenous Oz language when everyone in all the fairy countries speaks and writes in English and is never hinted to have any other language. Ozma goes on to explain that “once upon a time” four Wicked Witches joined forces and overthrew her grandfather, not father, who was the ruler Oz. The name Pastoria does not appear.
Mombi was the Wicked Witch of the North and had enslaved three generations of Ozma’s family: her grandfather, her father, and then finally her, though Mombi, in addition to the imprisonment, for some reason turned her into a boy. However, by the time the Wizard had arrived, Mombi had been conquered by the Good Witch of the North, while Glinda had defeated the Wicked Witch of the South. Weirdly, unlike the other witches, Mombi was left alive and got to keep her magic powers.