Part of the ruling philosophy of House Lionheart is that their nobles and subjects be ruled by two sovereigns: a male Prince and female Princess. Technically aliens could serve as Prince or Princess, but all Lionheart sovereigns have been human so far. Both positions are hereditary, but in case either throne becomes vacant due to a lack of an heir, the House of Aristocrats may select any Lionheart noble to serve on a vacant throne. The Prince and Princess, along with the House of Aristocrats and the House of Commons, serve as part of the governing troika of Lionheart-ruled space. The Prince serves as head of House Lionhearts military and police, while the Princess supervises the civilian governmental agencies. Both sovereigns jointly appoint the governors (generally Lionheart aristocrats) who provide local rule on planets and in solar systems under their rule. The Prince and Princess along with five judges elected by the House of Aristocrats serve as the supreme court for Lionheart-ruled space.