It's been several years since Mia Thermopolis (ANNE HATHAWAY) learned that she was an heir to the throne of the European country of Genovia where her grandmother, Clarisse Renaldi (JULIE ANDREWS), is the current queen. Having just turned 21 and being recently graduated from college, Mia travels to Genovia to become queen as Clarisse steps down.
Little do they or Clarisse's head of security Joseph (HECTOR ELIZONDO) and personal assistant Charlotte (KATHLEEN MARSHALL) know, however, that someone else wants to rule. And that would be Parliament member Viscount Mabrey (JOHN RHYS-DAVIES) who wants his nephew, Nicholas Devereaux (CHRIS PINE), to become king. To do so, he brings up an arcane rule that states that only a married woman can become Queen and gives Mia just 30 days to get hitched.
With Mia's good friend Lilly Moscovitz (HEATHER MATARAZZO) showing up, everyone at the palace races to find Mia a suitable groom, eventually settling on Andrew Jacoby (CALLUM BLUE), the Duke of Kenilworth. Neither is particularly pleased with the idea of an arranged marriage, but if that's what it takes, they'll do it. With the days counting down toward the deadline and pending nuptials, Mia tries to decide what's best for her and her country, all while Joe woos Clarisse and both Mabrey and Nicholas attempt to undermine the upcoming wedding so that the latter can become king.