Jayne Fincher/Princess Diana Archive/Getty Images
Perhaps Diana's most extraordinary influence on the royal family was her unprecedented vulnerability in the face of public scrutiny. She openly discussed her struggle with mental health (notably suffering from postpartum depression after giving birth to Prince William), and in her landmark interview with the BBC's Martin Bashir Diana remarked, "Well, maybe I was the first person ever to be in this family who ever had a depression or was ever openly tearful. And obviously that was daunting, because if you've never seen it before how do you support it?"
Years later, William and Harry have kept their mother's legacy alive by launching Heads Together, a campaign that works to change the U.K.'s conversation around mental health and wellbeing.