Munchkinland is the birthplace of Elphaba and Nessarose, the Wicked Witches of the West and East respectively. Elphaba had the birthright of being the leader of Munchkinland, but after Elphaba flew from the Emerald City, her father named Nessarose the successor.
Nessarose became the leader of Munchkinland and broke away from loyal Oz. She declared Munchkinland's independence and established the Free State of Munchkinland. She began instating new laws to prohibit Animals and informed her people to destroy the yellow brick road and passages into Munchkinland. She soon became known as the Wicked Witch of the East.
The Munchkins rejoiced after Nessarose's death, caused by Dorothy's house crushing her, but they soon moved on to attack the troops of the Emerald City and Loyal Oz.
In Wicked it was stated that the Thropps were one of about a dozen family Eminences in Munchkinland but were by far the most prominent. The Eminent Thropps claim the legitimacy of rule over all of Munchkinland. Their seat of power is Colwen Grounds located in Nest Hardings in Munchkinland.
In Out of Oz, the latest Eminence of Munchkinland was a witch called La Mombey. She moved the seat of power to Bright Lettins.