“I am the Witch of the North.”
“Are you a Munchkin?” asked Dorothy.
“No; but I am their friend, although I live in the land of the North.
…

“Who is Glinda?” enquired the Scarecrow.
“The Witch of the South. She is the most powerful of all the Witches, and rules over the Quadlings. Besides, her castle stands on the edge of the desert, so she may know a way to cross it.”
“Glinda is a good Witch, isn’t she?” asked the child.

–The Wonderful Wizard of Oz, L. Frank Baum, 1903

The movie deceived us into thinking that the Good Witch in attendance when Dorothy and Toto landed in Oz was called Glinda.

But that’s not right.

Glinda was the Witch of the South, but the Witch who stole the slippers, gave them to Dorothy, and set her on the path called the Yellow Brick Road was of the North.

Her name was Locasta.

In the second book (1904) which should have been called Ozma of Oz but wasn’t, this is confirmed:

“In the South Country rules a very delightful Queen called Glinda the Good, who I am sure will gladly receive us,” said the Scarecrow, getting into the Thing clumsily. “Let us go to her and ask her advice.”
…
“Now,” said old Mombi to the Queen, “let your soldiers deliver up this girl to Glinda. She will think she has the real Mombi in her power, and so will return immediately to her own country in the South.”

In the definitive modern retelling, called Wicked, Gregory MacGuire reiterates the movie’s error, by making Galinda into a poor little rich girl from Gillikin–in the North. Why? Possibly because he needed the people of the southern lands to have no eminence, Witchly or otherwise.

To be Anarchists, of a rather Neolithic sort, and to be at length exploited by the centralized royal power of the Emerald City because their own State was … ‘primitive’.

All of this matters a great deal.

I’m just not sure yet why.