Continuous vigils will be mounted by the Royal Company of Archers.
At 7.20pm, the King, the Princess Royal, the Duke of York and the Earl of Wessex will mount their own vigil, standing for a short time at the four corners of their mother’s coffin.
Prince Andrew, 62, was effectively sacked as a working royal in January after finding himself at the heart of one of the biggest royal scandals in recent memory, accused of raping and sexually abusing a young sex-trafficking victim.
Stripped of all royal titles and removed from virtually all facets of royal life, he had, until now, been frozen out of public life.
Even during the Platinum Jubilee celebrations he was only due to attend one event, the service of thanksgiving at St Paul’s Cathedral, but otherwise hidden away behind closed doors, forced to watch the festivities on television.
In the event, he was struck down with Covid and was not seen at all.
Both the King and the Prince of Wales have indicated that the Duke will have no formal role during their reigns.
But there was never a suggestion that he would be shunned from any part of the public mourning for the late Queen.
The Duke was incredibly close to his mother, who, aside from his ex-wife Sarah, Duchess of York, has proved his biggest champion during the last few years. He is understood to have spent an enormous amount of time with her recently, often making the short journey from his home, Royal Lodge, to Windsor Castle most days.
When news of the Queen’s sudden deterioration came through on Thursday morning, the Duke rushed to RAF Northolt, where he joined forces with Prince Edward, Princess Anne and Prince William to fly to Scotland.
It is not yet known whether they were aware, before take-off, that they would not make it to Balmoral before she died.
The Duke remained behind closed doors on Thursday night with his siblings, as well as Prince William and Prince Harry. While the two younger princes left, separately, on Friday morning, the family was later joined by Zara Tindall and Peter Phillips, Princesses Beatrice and Eugenie and Lady Louise Windsor and James, Viscount Severn.
Prince Andrew led the family on Saturday as they gathered for a small private service at Crathie Kirk before walking across the River Dee to inspect floral tributes at the gates of the Aberdeenshire estate.
He waved to onlookers, thanking them for their support, and also consoled his daughters as they struggled to keep their emotions in check.
Similarly, the family is aware that this is not the moment to leave the Duke and Duchess of Sussex out in the cold.
Differences will be set aside and the couple included in all relevant ceremonial events, just as the late Queen had wanted for the “much loved” members of her family.
The King made this clear on Saturday, when he said in his first televised address to the nation: “I want also to express my love for Harry and Meghan as they continue to build their lives overseas.”
Should doubts have remained, the Prince of Wales’s invitation for the Sussexes to join him and the Princess of Wales for a walkabout in Windsor on Saturday reinforced the point.
It is thought that the late Queen’s four children will take part in a second procession on Wednesday, as the coffin is taken by horse-drawn carriage from Buckingham Palace to the Palace of Westminster.
They could mount a second vigil at her coffin at Westminster Hall, where she will lie in state for four days.
Her grandchildren may take part in a vigil next Sunday, the evening before her funeral.