At Prince Philip's funeral on Saturday, Prince William and Prince Harry joined the procession behind their grandfather's coffin — with their cousin Peter Phillips walking between them.
As they entered St. George's Chapel in Windsor Castle, Prince William walked with Peter in the second procession. Behind them were Prince Harry and David Armstrong-Jones, the son of Princess Margaret and Antony Armstrong-Jones.
Listen below to the episode of our daily podcast PEOPLE Every Day for more on Prince Philip's funeral.
Princess Anne's only son has had a close bond with Prince William and Prince Harry throughout their lives, including other times of mourning.
Following the death of William and Harry's mother Princess Diana in 1997, Peter and his sister Zara rushed to Balmoral, Queen Elizabeth's estate in Scotland, to support their cousins. Peter was even seen joining his cousins and grandparents as they viewed flowers and other tributes left for Diana by members of the public outside the gates of Balmoral Castle.
Peter also walked beside his cousins at the 2002 funeral for their great-grandmother, the Queen Mother.
Peter grew up attending family events with Prince William and Prince Harry, including the royal family's annual walk to church on Christmas morning and Trooping the Colour, the yearly public celebration of the Queen's birthday.
Just as William and Peter were close during their childhoods, their own children now share a unique bond. Peter is father to two daughters — Savannah, 10, and Isla, 9 — who are frequently seen on outings with Prince George, 7, Princess Charlotte, 5, and Prince Louis, who will turn 3 on April 23. Savannah has even been seen shushing her little cousin Prince George on the balcony of Buckingham Palace during Trooping the Colour, despite his status as future monarch!
All of William and Peter's children were featured in the newly released photo of Prince Philip and Queen Elizabeth from 2018 with seven of their great-grandchildren. (They now have 10 great-grandchildren, with Meghan Markle and Prince Harry's daughter due this summer bringing the total to 11.)
Peter, who is Queen Elizabeth's eldest grandchild, did not inherit a royal title when he was born in Nov. 1977. According to the BBC, his parents Princess Anne and Captain Mark Philips "are said to have rejected an offer from the Queen of titles which would have enabled their children to be born into the peerage." They wanted their children to have normal lives.
At his birth, he was fifth in the line of succession to the throne. He is currently 16th.
Peter is not a working royal. Instead, he works for a living and has held positions at Jaguar, Williams F1 racing team, the Royal Bank of Scotland and SEL UK. Since 2012, he has had his own sports management company.
In 2008, Peter married Canadian Autumn Kelly at Windsor Castle. The two confirmed they had separated in 2020.
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Peter previously said he has a unique bond with his grandmother, the Queen.
"I've always been very close to my grandmother, and we speak often. She has been an inspirational person throughout my life," he told The Telegraph in 2016.