Prince William and Prince Harry to Stand Vigil at Queen Elizabeth's Lying-In-State

Prince William and Prince Harry will lead their cousins in a solemn vigil at Queen Elizabeth's lying-in-state on Saturday, PEOPLE has confirmed.

William, 40, and Harry, 38, will stand at opposite ends of the Queen's coffin at Westminster Hall and will be wearing military uniforms "at the King's request," according to a palace source.

Earlier this week it was announced that Harry — who served two tours of Afghanistan during his ten-year career in the British Army — would not be in uniform during the mourning period, yet this rule has been temporarily relaxed by King Charles III.

The decision was made without Prince Harry requesting a change, PEOPLE has learned. The Duke of Sussex was prepared to wear whatever was asked. His focus is on honoring his grandmother.

On Wednesday, Harry and Prince Andrew both wore morning suits during the solemn procession of the late Queen's coffin from Buckingham Palace to Westminster Hall.

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CHRISTOPHER FURLONG/POOL/AFP via Getty Queen Elizabeth lying in state

The two men did wear military medals on their suits in recognition of their military service, however, which in Prince Andrew's case included a medal for serving as a helicopter pilot in the Falklands War in 1982. In total, the Duke of York spent 22 years in the Royal Navy.

Alamy Stock Photo Prince William and Prince Harry at the unveiling of a Princess Diana statue in London on July 1, 2021.

Earlier in the week, a spokesperson for Prince Harry said, "His decade of military service is not determined by the uniform he wears, and we respectfully ask that focus remain on the life and legacy of Her Majesty Queen Elizabeth II."

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According to the palace source, William will stand at the head of Her Majesty's coffin during the 15-minute vigil, flanked by Zara Tindall and Peter Phillips.

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Chris Jackson/Getty Images Prince William and Prince Harry

Harry will stand at the foot of the coffin alongside Princess Beatrice and Princess Eugenie. Their other cousins Lady Louise Windsor and Viscount Severn will stand at the middle of the coffin.

The vigil takes place a day after the 'Princes' Vigil' of King Charles III, Princess Anne, Prince Andrew and Prince Edward. At that vigil, Andrew is also being permitted to wear a uniform despite not being a working member of the royal family.

"The grandchildren, at the King's invitation, are very keen to pay their respects – just as their parents are doing the evening before," a royal source says.

The Queen, who died on September 8 at age 96 in Scotland, made her last journey from Buckingham Palace to Westminster Hall on Wednesday.

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MARCO BERTORELLO/AFP via Getty Images Prince Harry

The procession included her four children and several of her grandchildren, including Prince William, Prince Harry and Peter Philips.

William and Harry's wives, Kate Middleton and Meghan Markle, traveled to Westminster Hall by car, as did Queen Camilla and Sophie, Countess of Wessex, the wife of Prince Edward.

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The coffin was draped with the Royal Standard, on which the Imperial State Crown (which was worn by Queen Elizabeth for her coronation and at State Openings of Parliament) was placed on a velvet cushion along with a wreath of flowers. The wreath includes white roses, spray white roses, white dahlias as well as foliage including pine from the gardens of Balmoral and pittosporum, lavender and rosemary from the gardens at Windsor.