Traditionally, the planet Etheria was governed by a planetary, hereditary, worldwide monarchy, with the throne in the royal family composed of the ancestors of Queen Angella and her daughter Glimmer. Castle Bright Moon was the historical seat of the Etherian planetary regime. Like the government of it's sister planet Eternia (see Government of Eternia), the planetary monarch of Etheria probably was in practice a limited monarch, with various cities, local kingdoms, regions, and factions exercising various degrees of independent autonomy, and the planetary ruler practically had to consult with local and regional leaders before making laws.
The First Ones were the de facto rulers of the world before the establishment of the monarchy. For some unknown reason, the First Ones vested nominal political power in certain, more human leaders of Etheria (i.e. ancestors of Angella).
Angella was likely the real ruler of Etheria, while her husband King Micah was merely a spouse and possibly a close political advisor. Glimmer would be the heir to the planetary throne.