The Accession Council will convene on Saturday in a ceremony that will be televised for the first time, as Charles III is proclaimed King of the United Kingdom.
Flags that have been lowered to half-mast to mourn the Queen’s death will fly at full mast after the ceremony.
This will be followed by further proclamations before the flags return to have mast on Sunday.
Although the throne automatically passed to Charles upon the death of the Queen, the Accession Council is the formal proclamation of the successor to the monarch.
Proceedings begin at St. James’s Palace in the morning at around 10:00 BST. At around 11:00 BST, the first public proclamation will be delivered from the St. James’s Palace’s Friar Court balcony, which will be greeted by a trumpeters’ fanfare and gun salutes from sites including Hyde Park and the Tower of London.
Charles’ wife Camilla, now Queen Consort, will attend the council alongside Charles, as will their son Prince William who has now been bestowed the title of Prince of Wales, formerly held by Charles himself.
The ceremony will end with Charles making a personal statement about the death of his mother and swearing an oath to preserve the Church of Scotland and the signing of the proclamation by the new King and privy councillors. It will also receive the signatures of the Queen Consort, the Prince of Wales, the Archbishop of Canterbury, the Lord Chancellor, the Archbishop of York and the prime minister.
Charles had addressed the nation on Friday evening, expressing “profound sorrow” in the wake of Her Majesty’s passing and promising to serve the country with the same devotion as his “darling mama” had.
He also shared his hope that citizens of the UK and the Commonwealth would “remember” the Queen and “draw strength from the light of her example” to all.
Charles took a moment to wish Prince William and his wife Catherine well as they took on their new titles in Friday’s televised address, and spoke of his “love for Harry and Meghan” as they set about building their new life abroad.