The Duke of Edinburgh, Prince William, Earl Spencer, Prince Harry and the Prince of Wales follow the coffin of Diana, Princess of Wales in September 1997. Photo / Getty Images
It was an image in time which captured Prince Philip's loyal and thoughtful traits - walking with young Prince William and Prince Harry at the funeral procession for Princess Diana.
While it was a sombre occasion, it showcased a side many hadn't seen of Philip.
Now, after his death on April 9, aged 99, it has been revealed why Prince Philip walked with his grandsons following the death of their mother.
The Duke of Edinburgh was extremely concerned about the emotional wellbeing of his young grandsons during preparations for Diana's funeral in 1997.
A former government relations director told the UK's Evening Standard the family were in conversation about Diana's funeral plans when suddenly Prince Philip spoke.
"We were all talking about how William and Harry should be involved and suddenly came Prince Philip's voice. We hadn't heard from him before, but he was really anguished.
"It's about the boys,' he cried. 'They've lost their mother.'"
The night before the funeral, Philip went one step further, turning to his grandsons and saying "I'll walk if you walk".
In an interview with ITV following Philip's death, Princess Anne recalled how her father helped William and Harry deal with their grief.
"I seem to remember them saying that, in fact, it was a question of, 'If you'll do it, I'll do it,'" she told ITV.
"That was him as a grandfather ... 'If that's what you want to do and if you want me to be there, I will be there.'"
The next day, Philip was seen walking alongside William, 15, and Harry, 12, during the procession from Kensington Palace to Westminster Abbey in London.
William and Harry were also joined by their father Prince Charles, and Diana's brother Earl Spencer.
It wasn't just Prince Philip who stepped up to support William and Harry.
In an interview with the BBC in 2017, Prince Harry opened up about his mother's funeral and revealed how his father Prince Charles supported the family.
He also detailed the family's decision to include him and William in the funeral.
"One of the hardest things for a parent to have to do is to tell your children that your other parent has died.
"How you deal with that I don't know but, you know, he was there for us.
"It wasn't an easy decision [to include William and I] and it was a sort of collective family decision to do that ... there is that balance between duty and family and that's what we had to do."
Prince William admitted it was difficult to balance "between me being Prince William and having to do my bit, versus the private William who just wanted to go into a room and cry, who'd lost his mother".