The Princess Diaries is a romantic comedy film in which Anne Hathaway stars as Mia Thermopolis, a socially awkward teenager who discovers that she is the heir to the throne of a small European country. The film follows Mia's journey as she navigates the challenges of royal life, with the help of her grandmother, played by Julie Andrews. Hathaway's endearing performance and the film's heartwarming storyline make The Princess Diaries a beloved classic for audiences of all ages.