In this April 24, 1991 file photo, Britain's Princess Diana, the Princess of Wales, hugs and plays with an HIV positive baby in Faban Hostel, San Paulo, on the second day of her visit to Brazil. (AP File Photo)
London: There was a time when scenes like this at London's Olympic Park would not have happened: Prince William, the heir to the British throne, sprinting down the track with his wife, the Duchess of Cambridge, and his brother, Prince Harry, to the cheers of other runners in a relay race this year promoting mental health.
It was so human. So accessible. So Diana.
Princess Diana, a preschool teacher thrust into the glare of celebrity by her marriage to Prince Charles, dragged Britain's ribbon-cutting royals into the modern world.
She made a direct connection with the public —once running her own race in a flowing white skirt and baggy sweater — and promoted causes far from the mainstream at the time, like land mine removal and AIDS research.
That link lives on through her two sons, who have adopted their mother's more personal approach to monarchy and in the process reinvigorated the institution.
"She was the first royal who really took the public's heart," said Sandi McDonald, 55, from south London, outside an exhibit of the late princess' dresses at Kensington Palace. "I think her sons are the same - the public just loves them."
William and Harry are the most obvious reminder of Diana's impact. They have spoken openly about their own mental health issues over losing a parent while so young and breaking down taboos just as their mother embraced AIDS patients to ease fears about the disease.
But the princess' most far-reaching legacy is her popularization of the idea that celebrities can use their ties to millions of people they've never met to effect change.
Having been swallowed up by the royal machine when she was barely 20, Diana found her way in life after realizing that the public was fascinated by her every thought, says sociologist Ellis Cashmore.
Diana was able to manipulate that interest to her own advantage, promoting causes such as land mine clearance and telling her side of the story when her marriage collapsed amid Prince Charles' relationship with Camilla Parker Bowles, who later became his second wife.