Almost 20 years after her death, the princes were joined at the service by the Duchess of Cambridge, Prince George and Princess Charlotte. Prince Charles was in Canada with Camilla on an official tour.
Staged at Diana’s burial site on the Oval Lake at Althorp House in Northamptonshire, the solumn, private service was conducted by the Archbishop of Canterbury, Justin Welby.
The Princess died on August 31, 1997 in a car crash in Paris, when William was aged 15 and Harry was just 12.
The service marked the beginning of a difficult few months for William and Harry as they remember their mother.
BBC royal correspondent Peter Hunt wrote: “They were traumatised children when she died. Harry has spoken of how he shouldn’t have been made to walk behind Diana’s coffin. William has expressed his considerable regret that they weren’t old enough to do more to protect her.
“Twenty years on, together, they’re taking control of how she will be remembered.”
The brothers have commissioned a statue to commemorate their mother, which will be unveiled in public in the public grounds of her former home at Kensington Palace.
In a new BBC dodcumentary with the working title Diana, William says: “Part of the reason why Harry and I want to do this is because we feel we owe it to her. I think an element of it is feeling like we let her down when we were younger. We couldn’t protect her.”
Harry adds: “I think it’s never going to be easy for the two of us to talk about our mother, but 20 years on seems like a good time to remind people of the difference that she made, not just to the royal family, but also to the world.”