Queen of Genovia Mia Thermopolis (Anne Hathaway) will be without a key guardian in The Princess Diaries 3. Julie Andrews starred alongside Hathaway in 2001's The Princess Diaries, playing Mia's grandmother and the queen of the fictional country of Genovia. She reprised the role three years later in The Princess Diaries 2: Royal Engagement, which ended with Clarisse stepping down as Mia became queen. The decision also makes sense considering where The Princess Diaries 2 left the characters. Based on the Princess Diaries books by Meg Cabot, the sequel remains in development.