Prince Philip was a supportive grandfather to Prince William following Princess Diana’s death.

The Duke of Edinburgh did an incredible effort to help the Duke of Cambridge as he grieved for the untimely death of his mother. In an unearthed documentary titled “Prince William at Thirty,” Prince Philip’s effort to help Prince William walk at Princess Diana’s funeral was discussed.

“When the day of the funeral came, I think William was still uncertain as to whether he would agree to walk behind his mother’s coffin,” former BBC royal correspondent Jennie Bond said.

To show his support and love to Princess Diana’s eldest son, Prince Philip reportedly offered to walk with Prince William.

“Grandfather Prince Phillip said: ‘If I walk, will you?’” Lady Elizabeth Anson, Queen Elizabeth II’s cousin, revealed.

“And I think Prince William thought it was such a wonderful thing of his grandfather, and I think it’s a decision he’ll never ever regret.”

Former ITN royal correspondent Nicholas Own found it incredible to see the three generations of royal men walking behind Princess Diana’s coffin – Prince Philip, Prince Charles, and Prince William and Prince Harry.

He added no one expected to see the royals in that way. He also said that Princess Diana and Prince Philip had a not-so-smooth relationship.

Meanwhile, Prince William and Prince Harry were confused and shocked by the public’s reaction to their mother’s death. The Duke of Cambridge admitted that he was asking himself during the funeral why they were crying, upset and emotional when they didn’t know Princess Diana personally. He felt protective of his mom but as he grew up, he learned what Princess Diana gave to the world and understood them.

Other reports claimed that Prince William refused to join Prince Charles in walking behind Princess Diana’s coffin. However, he only agreed when Prince Philip joined them and walked beside him. Kate Middleton’s husband confessed that it was “one of the hardest things” he had to do.

Prince Harry shared the same sentiment. The Duke of Sussex confessed to Newsweek that no child should be asked to do it under any circumstances before adding, “I don’t think it would happen today.”

Prince Philip and Prince William
Prince Philip reacted bluntly after learning that his grandson Prince William was planning to drop out of school. Pictured: Prince Philip and Prince William enjoy the build up to the 2015 Rugby World Cup Final match between New Zealand and Australia at Twickenham Stadium on Oct. 31, 2015 in London. Getty Images/Phil Walter