With the Queen’s advanced years, there has been a gradual devolving of some of the more arduous public engagements to younger members of the royal family.
Should the Queen, 95, be temporarily indisposed, such as through illness, or be out of the country, the counsellors of state can step in.
Today these are Charles, Prince William, Prince Harry and the Duke of York, according to the royal family’s official website.
Indeed, the Queen has missed it on two occasions, in 1959 and in 1963 when she was pregnant with Andrew and then Edward.
“Queen Victoria often wasn’t there towards the end of her reign,” Bogdanor noted.
In the absence of any details from Buckingham Palace on the tests she has undergone, which remain private, and its insistence that she is in “good spirits”, it can be assumed she is, naturally, slowing down but otherwise well.
Meanwhile, Charles, Camilla, William and Kate will be out in force in Glasgow, including attending a reception for world leaders.
Charles already lays the wreath on his mother’s behalf at the Cenotaph on Remembrance Sundays, and has done since 2017.
Since she no longer undertakes long-haul travel, Charles already represents her on official visits overseas, including at the biennial Commonwealth heads of government meeting.
“If the transition works well, it should just all be very, very subtle.
In his role organising the Jubilee Walkways and the Commonwealth Walkways, Vickers said he strove for “maximum exposure of the Queen and minimum time spent by her.
The Covid pandemic has forced the Queen to turn to virtual engagements, which are less tiring, “and she has taken to Zoom like a prawn into aspic,” Vickers said.