Amelia Mignonette Grimaldi Thermopolis Renaldo (Amelia Mignonette Thermopolis Renaldi in the film series), also known as Mia Thermopolis, is a fictional character and the protagonist of The Princess Diaries novels by Meg Cabot. The story revolves around her diary, which she writes in religiously, and her relationships with her best friend Lilly Moscovitz, her long-time boyfriend and "the love of her life" Michael Moscovitz, her grandmother, and others.