In Meg Cabot’s The Princess Diaries, Mia Thermopolis is heir to the fictional country of Genovia.
Mia begins the novel as an ordinary teenager in Manhattan, but learns that her father is the prince of Genovia. Because her parents were never married, Mia is next in line to the throne. Her grandmother, Clarisse Renaldi, then takes responsibility for teaching her royal etiquette and diplomacy.
Genovia is a small European principality created for the series. It is fictional, so it should not be confused with Geneva, Switzerland, or with real European monarchies such as Monaco and Liechtenstein. The books use Genovia as both a royal setting and a source of comic culture shock for Mia.
The first novel was published in 2000 and launched a long series. The 2001 film adaptation, starring Anne Hathaway as Mia, also uses Genovia as the setting, although several plot details differ from the book.