In the Novels
The ruling monarchy of Oz passes down the female line, however, when his wife Ozma the Bilious died, Pastorius became the Ozma Regent, until their daughter is old enough to take the throne.
When the Wizard invaded the land and overthrew the monarchy in a coup d'état, Pastorius was assassinated. Baby Ozma was given to La Mombey, a witch from Gillikin and a former adviser to Pastorius. The witch transformed the princess into a kitchen boy she would later call "Tip".