There are two celebrity princesses celebrating a birthday today! One portrayed royalty on the silver screen, while the other went from film to the real thing — Anne Hathaway channeled a regular girl thrust into royalty in The Princess Diaries, while Grace Kelly starred in movies like Dial M For Murder, Rear Window, and To Catch a Thief before marrying Monaco's Prince Rainier III in 1956. They've also both experienced some sweet Oscar bliss; in 2010, Anne hosted the ceremony with James Franco, and in 1955, Grace won the best actress award for her role in The Country Girl. Perhaps most importantly, both leading ladies have risen to fame and subsequently become fashion icons of their days; not only do we have Grace Kelly to thank for the Hermès Kelly bag, but she was also the picture of poise, polish, and well, grace — something that 30-year old red-carpet beauty Anne Hathaway has also perfected. We're celebrating both birthday girls with photos of their unmistakable similarities and stately style — click through to see them all!