LONDON — Queen Elizabeth II’s eight grandchildren stood vigil by their grandmother’s coffin Saturday at Westminster Hall ahead of her state funeral, slated for Monday.
The observance, traditionally known as the Vigil of the Princes, lasted 15 minutes.
Both Prince William, Prince of Wales, and Prince Harry, Duke of Sussex wore military dress, with the former donning the Blues and Royals No. 1 uniform, the Garter Sash, the Garter Star, the Golden, Diamond and Platinum Jubilee Medals and RAF pilot wings, the BBC reported.
[ King Charles III, Prince William surprise mourners filing past Queen Elizabeth II’s coffin ]
Harry wore a Blues and Royals No. 1 Uniform, KCVO Neck Order and Star, Afghanistan Operational Service Medal, Golden, Diamond and Platinum Jubilee medals and Army Pilot Wings, the news outlet reported.
William and Harry, sons of King Charles III, were joined by cousins Princesses Beatrice and Eugenie, Zara Tindall and Peter Phillips, and Lady Louise Windsor and James, Viscount Severn, all of whom wore black, according to The Guardian.
[ Queen Elizabeth II dies: King Charles III, siblings hold vigil around coffin ]
According to the BBC, Peter Phillips is the eldest grandchild at 44, while James, Viscount Severn is just 14.
The Vigil of the Princes was first observed following the 1936 death of George V, “when his four sons – King Edward VIII, Prince Albert (the future King George VI and the late Queen Elizabeth II’s father) and Princes Henry and George – stood around the four sides of their father’s coffin at Westminster Hall,” the news outlet reported.
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Prince Harry, Duke of Sussex arrive to hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Ian Vogler-WPA Pool/Getty Images) (Ian Vogler/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Prince Harry, Duke of Sussex, Princess Eugenie of York, Princess Beatrice of York, Peter Phillips, Zara Tindall, Lady Louise Windsor, James, Viscount Severn arrive to hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Ian Vogler-WPA Pool/Getty Images) (Ian Vogler/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Prince Harry, Duke of Sussex, Princess Eugenie of York, Princess Beatrice of York, Peter Phillips, Zara Tindall, Lady Louise Windsor, James, Viscount Severn (obscured) arrive to hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Ian Vogler-WPA Pool/Getty Images) (Ian Vogler/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Prince Harry, Duke of Sussex, Princess Eugenie of York, Princess Beatrice of York, Peter Phillips, Zara Tindall, Lady Louise Windsor, James, Viscount Severn arrive to hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Ian Vogler-WPA Pool/Getty Images) (Ian Vogler/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Prince Harry, Duke of Sussex, Princess Eugenie of York, Princess Beatrice of York, Peter Phillips, Zara Tindall, Lady Louise Windsor, James, Viscount Severn arrive to hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Ian Vogler-WPA Pool/Getty Images) (Ian Vogler/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Lady Louise Windsor is seen during a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Zara Tindall and Lady Louise Windsor hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Zara Tindall, Lady Louise Windsor and Princess Beatrice of York are seen during a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Princess Beatrice of York and Prince Harry, Duke of Sussex are seen during a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales holds a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Peter Phillips and James, Viscount Severn hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Queen Elizabeth II 's grandchildren (L-R) Prince William, Prince of Wales, Princess Beatrice, Harry, Duke of Sussex and Peter Phillips hold a vigil beside the coffin of their grandmother as it lies in state on the catafalque inside Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Aaron Chown - WPA Pool/Getty Images) (Aaron Chown/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Zara Tindall, Lady Louise Windsor and Princess Beatrice of York hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Lady Louise Windsor, Princess Beatrice of York and Prince Harry, Duke of Sussex are seen during a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince Harry, Duke of Sussex, Princess Eugenie of York and James, Viscount Severn (C) hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Aaron Chown-WPA Pool/Getty Images) (Aaron Chown/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince Harry, Duke of Sussex and Princess Beatrice of York hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Aaron Chown-WPA Pool/Getty Images) (Aaron Chown/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Peter Phillips, James, Viscount Severn, Zara Tindall, Lady Louise Windsor and Princess Beatrice of York hold a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (Chris Jackson/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Queen Elizabeth II 's grandchildren (left to right, from bottom) Prince William, Prince of Wales, Peter Phillips, Zara Tindall, James, Viscount Severn, Lady Louise Windsor, Princess Eugenie, Princess Beatrice, and the Prince Harry, Duke of Sussex, depart after holding a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Yui Mok-WPA Pool/Getty Images) (Yui Mok/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Prince William, Prince of Wales, Peter Phillips, Zara Tindall, James, Viscount Severn, Lady Louise Windsor, Princess Eugenie of York, Princess Beatrice of York and Prince Harry, Duke of Sussex are seen during a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (Chris Jackson/Getty Images)
William, Harry, cousins stand vigil by Queen Elizabeth II's coffin LONDON, ENGLAND - SEPTEMBER 17: Sophie, Countess of Wessex and Prince Edward, Earl of Wessex arrive for a vigil in honour of Queen Elizabeth II at Westminster Hall on September 17, 2022 in London, England. Queen Elizabeth II's grandchildren mount a family vigil over her coffin lying in state in Westminster Hall. Queen Elizabeth II died at Balmoral Castle in Scotland on September 8, 2022, and is succeeded by her eldest son, King Charles III. (Photo by Chris Jackson/Getty Images) (CHRIS Jackson GETTY IMAGES/Getty Images)