Almost 20 years after their mother, Princess of Wales, died, Prince William and Prince Harry attended a special ceremony to rededicate her grave.

On what would have been Diana’s 56th birthday, an emotional private ceremony was conducted at her family home in Northamptonshire.

While 3 million people turned out to grieve the princess’s death 20 years ago, lining the path of her coffin as it was taken from Kensington Palace to Westminster Abbey, her family’s burial and grieving took place discreetly on her family’s estate, Althorp House, some 70 miles north of the city.

The Duchess of Cambridge, Prince George, and Princess Charlotte also attended the event.

The ceremony was presided over by Archbishop of Canterbury Justin Welby.

It comes after both Princes publicly addressed their personal struggles after their mother’s death, with Harry saying he was in “total chaos” following his mother’s death.

“My mother had just died, and I had to walk a long way behind her coffin, surrounded by thousands of people watching me, while millions more did on television. I don’t think any child should be asked to do that, under any circumstances. I don’t think it would happen today.” Both Prince William and Harry also spoke out about the aftermath of their mother’s untimely death in an upcoming BBC documentary, revealing that they both felt they had let Diana down in life,” the Prince told Newsweek.

“Part of the reason why Harry and I want to do this is because we feel we owe it to her,” William said. “I think an element of it is feeling like we let her down when we were younger. We couldn’t protect her. We feel we at least owe her 20 years on to stand up for her name and remind everybody of the character and person that she was. Do our duties as sons in protecting her.”

“When she died there was such an outpouring of emotion and love which was quite, which was quite shocking. It was beautiful at the same time, and it was amazing, now looking back at it, it was amazing that our mother had such a huge effect on so many people,” Prince Harry said.

She was put to rest inside a walled, 500-acre park on the Spencer family estate, which is visited by thousands of tourists each year, and was honored with a simple ceremony on a tiny island. She was then interred in a lake.

The Princess of Wales died in a vehicle accident in Paris on August 31, 1997, when the Duke of Cambridge was 15 and his brother was 12.

The two Princes have also commissioned a statue for Kensington Palace to commemorate the 20th anniversary of their mother’s death.

“The service, which will fall on what would have been the Princess’s birthday, will be conducted by The Archbishop of Canterbury and attended by her family,” Kensington Palace stated in a short statement.

While there are memorials dedicated to Diana around Althorp’s 13,000 acres, her ultimate resting site has been and continues to be off-limits to the public.

Both princes have become famous mental health advocates, urging people to talk freely about their feelings rather than bottling them up, and William said in April that the shock of losing his mother remained.

“You never get over it, it’s such an unbelievably big moment in your life that it never leaves you. You just learn to deal with it,” he said.