Fifteen years ago, Anne Hathaway made her film debut in "The Princess Diaries" as geeky teen Mia Thermopolis, who learns she's really a princess of a country called Genovia.

Cue fabulous makeover, happy ending and a sequel. Director Garry Marshall, costar Julie Andrews and Hathaway were just talking about reuniting for a third "Princess Diaries" film before Marshall's untimely death on July 19.

Here are some things you might not know about the 2001 comedy, which opened on August 3, 2001.1. Hathaway landed the part of Mia partly because Garry Marshall's granddaughters saw her audition tape and said she had the best "princess hair."

2. Among the actresses who reportedly turned down the role of Mia: Drew Barrymore, Reese Witherspoon, and Kate Hudson.3. Hathaway only had one audition for the film. As she told Access Hollywood in 2001, "I was on my way to New Zealand for an independent movie and I had a 26-hour stopover in Los Angeles. I asked, 'Can I do some auditions? What about 'The Princess of Tribeca' -- which is what this was called then." She met with Marshall and "got really nervous and, at some point, fell out of my chair... I think that's what impressed him the most." Disney wanted her to do a screen test, but she couldn't because of her trip to New Zealand. Luckily, her audition tape was good enough to get her the job.

4. Hathaway's klutziness that landed her the part also made for a memorable scene in the movie: Her trip over the bleachers wasn't scripted, but Marshall loved it and kept it in.5. Mia's cat Fat Louie? Hathaway's real-life pet (above). It had to be doubled by three different cats, one that could be carried, one that would sit perfectly still, one who could jump, and the last one who sits on the envelope at the end of the movie.

6. That was also the actress's real dental retainer! Marshall added it to the script when he learned she used to wear one. She managed to find it and brought it to set.
7. "The Princess Diaries" is the only major role for musician Robert Schwartzman, who prefers to focus on his band, Rooney. (They make a small appearance in the film.) Film definitely runs in his family: He's the son of actress Talia Shire, his brother is "Rushmore" star Jason Schwartzman, and his cousin is Sofia Coppola. He had a small role in her film, "The Virgin Suicides."

8. During post-production, Schwartzman reportedly wanted to change his name to Robert Cage in honor of his cousin, Nicolas Cage (who was born Nicolas Coppola). But the promo material had already been finalized, so he kept his real name.9. Hathaway's bushy hairpiece was so unruly, it was nicknamed "The beast." And her out-of-control fake eyebrows took an hour to apply since each hair had to be individually applied.

10. Marshall loves to use the same actors over and over: Hector Elizondo is in all of his films. He also loves to repeat a gag. In the scene where Mia drops a grape at the dinner table and sets off a comical chain of accidents, the waiter says, "It happens all the time." The same actor delivered the same line in "Pretty Woman" (1990) when Julia Roberts accidentally sends a snail flying while trying to eat escargots. (Slippery little suckers.)
11. "The Princess Diaries" was a family affair: The girls seeking Mia's autograph are Lilly and Charlotte, Marshall's twin granddaughters. And Clarisse's secretary Charlotte, is played by Kathleen, his daughter.

12. Marshall cameos as a guest at Genovia's annual independence ball, as does sister Penny Marshall.
13. The romance between Queen Clarisse Renaldi (Julie Andrews) and Joseph (Hector Elizondo) wasn't in the script, and the two actors improvised their dance scene.

14. Meg Cabot, who wrote "The Princess Diaries" book series, had no input on the film. As she wrote on her site, "People always ask me if I 'helped' with the 'Princess Diaries' movie. I really didn't. I don't think Garry Marshall needs 'help' to make a movie... especially 'help' from a novelist who has absolutely no experience in film-making! And good thing I didn't help with the first movie, because it did just fine without me."15. Hathaway told HuffPost Live that "Princess Diaries" was "a great first job," but she struggled to land more serious acting gigs afterwards. "It was hard get into rooms, to be taken seriously for roles that weren't princesses."

16. Hathaway did not get to keep the tiara she wears in the movie, but Disney did send another one home with her.17. Whitney Houston, who produced the film, surprised Gary Marshall on set with a giant cake and sang "Happy Birthday" to him.