Now the Queen has died, Prince Charles, 73, will automatically and immediately become king.
There had been suggestions Charles would step aside to allow the monarchy to pass to his eldest son Prince William, but royal watchers considered this unlikely and so it has proved.
Charles' siblings will kiss his hands following the death of their mother.
British officials have been preparing for the Queen's death since the 1960s under a plan called "London Bridge is down", the phrase to be used to convey the news through official channels.
The first official to deal with the news was planned to be Sir Edward Young, the Queen's private secretary.
Young's job was then to contact the British prime minister and from the Foreign Office's Global Response Centre, at an undisclosed London location, the news was then to be dispatched to the 15 governments outside the UK where the Queen is also the head of state - New Zealand among them - and the 36 other nations of the Commonwealth for whom she has served as a symbolic figurehead.
The palace website has switched to a single page, showing the same announcement as made to world media as that pinned by a footman in mourning clothes to the gates of Buckingham Palace.
On the day after the Queen's death, at a meeting of the Accession Council, Charles, the Prince of Wales, will be proclaimed King Charles III - unless he chooses another name - and a 41-gun salute will be fired in London's Hyde Park.
His wife Camilla will be known as Queen Consort, a request made by Elizabeth to mark the 70th anniversary of her reign in February 2022.
Unlike the monarchy, the Queen's role as head of the Commonwealth is not hereditary.
There was uncertainty over Charles' getting the job, until it was announced in 2018 by the group's heads-of-government meeting in London that he would, fulfilling the Queen's wish.
According to royal protocol, the Queen's body will be moved to Buckingham Palace.
Preparations will be made for a state funeral led by the Archbishop of Canterbury.
On the fourth day after the Queen's death, she will be moved to Westminster Hall to lie in state for four days.
Hundreds of thousands of mourners are expected to file past her coffin - for comparison, more than 200,000 members of the public paid their respects to the Queen Mother when she died in 2002.
On the ninth day following her death the funeral will be held at Westminster Abbey, according to the Guardian.
Leaders and heads of state from the Commonwealth and other countries will attend, and it's likely the public will line the route of the funeral cortege.
Finally, the Queen will be buried in a tomb at St George's Chapel, which is in the grounds of Windsor Castle.
Her husband, who died in April 2021, will be moved from his initial resting place, a royal vault of St George's Chapel, to lie with her.
Second-hand clothing can be a reservoir for many potentially dangerous microbes.