It's been almost 19 years since Princess Diana's tragic car accident in Paris. Millions mourned around the globe. The beloved "people's princess" — who was only 36 at the time of her death — would have turned 55 on July 1. Despite her brief life, she left an enduring impact on the royal family and the world. Her greatest legacies, of course, are her sons. (And Prince William is already putting family before propriety.) "I don't go by a rule book, because I lead from the heart, not the head, and albeit that's got me into trouble in my work, I understand that," she said in 1995. "But someone's got to go out there and love people and show it." Here, we celebrate the rebellious royal for all the ways she flouted tradition.