Today, we recognize Princess Diana on what would have been her 53rd birthday. Before Kate Middleton came the Princess of Wales, mother of Prince William and Prince Harry, who captivated the public with her presence and grace. The classic beauty was truly one of a kind, and went beyond simply fulfilling traditional royal duties and became heavily involved in charity work during her lifetime. Princess Diana worked as president of the Great Ormand Street Hospital for Children and of Barnado’s, which cared for vulnerable children and young adults, and also lead campaigns for leprosy and AIDS awareness around the world.

Somehow, the Princess of Wales also managed to fit “style icon” into that packed schedule. From her fitted skirt suits to more casual ensembles, click through our gallery to see Princess Diana’s most iconic looks ever.