It was one of the most moving moments in the days following the death of Queen Elizabeth II.
Two years ago today, King Charles solemnly led his siblings into Westminster Hall to carry out the 'Vigil of the Princes'.
Charles and Princess Anne, Prince Andrew and Prince Edward all stood in stoic silence around their late mother's coffin for ten minutes as her body lay in state.
Four days earlier, they had performed the same ritual at St Giles' Cathedral in Edinburgh, where Queen Elizabeth's coffin initially rested following her death on September 8.
The tribute dates back to the death of King George V in 1936, when the monarch's four children all stood guard around his coffin.
The day after Charles' tribute alongside his siblings, the Queen's eight grandchildren - including the warring Prince William and Prince Harry - performed their own vigil.
Charles wore a Navy Admiral's uniform, Anne was dressed in a Colonel of the Blues and Royals uniform and Edward was wearing Royal Honorary Colonel of the Royal Wessex Yeomanry dress.
Unlike at the previous vigil, where Andrew had worn a morning suit, the outcast Duke of York - who was stripped of his armed forces patronages earlier in 2022 - was dressed in the full uniform of a Vice Admiral of the Royal Navy.
He was given special permission to wear the military dress as a 'final mark of respect' to his mother.
The Queen's coffin had been lying in state since September 14, after being taken down from Scotland.
Charles stood at the head of the casket while Edward and Anne - the first female royal to perform the vigil - guarded the sides and Andrew stood at the foot.
The siblings then stepped forward before turning around to stand guard with their head bowed for around 10 minutes.
Meanwhile, members of the public continued to file past the coffin.
The next evening, Prince William led Prince Harry, Princesses Beatrice and Eugenie, Zara Tindall, Peter Phillips, Lady Louise Windsor and James, Viscount Severn in a final royal vigil.
At 6pm on September 17, they walked down the steps one a time and took their places around the coffin.
All were dressed in black, with Prince William and Harry wearing military uniform.
Harry had previously not been allowed to wear his uniform for the public mourning events because he is not a working royal, but sources said the King decided his youngest son could wear military dress for the vigil.
Both he and William wore a Blues and Royals uniform, while the Duke also displayed the KCVO Neck Order and Star, Afghanistan Operational Service Medal, Golden, Diamond and Platinum Jubilee medals and Army Pilot Wings.
Prince William wore the the Garter Sash, the Garter Star, Golden, Diamond and Platinum Jubilee medals and RAF Pilot Wings.
There was silence as members of the public looked on, with the only sound being the grandchildren's footsteps on the stone.
Prince William stood at one end of the coffin while Prince Harry stood at the other, the remaining grandchildren took their places along the side.
All eight bowed their heads in respect while mourners continued to move through the room quietly.
The then Earl and Countess of Wessex also watched on as the grandchildren held vigil.
At 6.15pm, three taps sounded and the grandchildren ended their vigil, leaving in synchronised steps as Prince William led the way.
The Queen lay in state until the morning of September 19 and hundreds of thousands of mourners queued overnight to pay tribute to the late monarch.
At its height, the queue was up to 10 miles long - with 6.9miles of that being the distance between Westminster and Southwark, plus a three-mile zigzag queue in Southwark Park.
Both Britons and foreigners embraced the long, slow, procession across central London to enter the solemn hall amid freezing temperatures.
David Beckham, who queued for 14 hours to pay his respects, was among the celebrities who waited in line.
A 96-year-old war veteran who saw the Queen's grandfather, George V, lying in state in 1936 also attended.
