The planet Naboo had a constitution. The constitution limited the monarch of the planet to two terms in office, although it was almost amended in 28 BBY to allow for Queen Padmé Amidala to continue to serve for more terms after the Invasion of Naboo but she refused to do so, though she admitted to her handmaiden, Sabé that she was tempted to.
In 22 BBY, Amidala discussed the matter with Jedi Padawan, Anakin Skywalker, saying that she was relived when her two terms were up.
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