London: Charles III will be formally proclaimed King of the United Kingdom at a historic ceremony at St James's Palace on Saturday.
The proclamation is a public announcement of the accession of the new monarch.
Charles,73, Queen Elizabeth II’s eldest son, automatically became King after his mother’s death, and traditionally an Accession Council is convened within 24 hours of a sovereign’s death. But the late announcement of the Queen’s death meant there was insufficient time to organise it for Friday.
There will be a multi-stage process publicly announcing his new title of King Charles III.
Flags lowered in mourning for the late Queen will fly full-mast after the Accession Council, which will be televised for the first time.
A wave of further proclamations will take place across the UK until Sunday when flags will return to half-mast.
The Accession Council, which is made up of senior Cabinet ministers, judges and leaders of the Church of England, and will meet at 10 am, without Charles, at the State Apartments of St James's Palace in London to formally proclaim him as the new sovereign.
At the council, the King will then make a personal declaration about the death of the Queen and make an oath to preserve the Church of Scotland - because in Scotland there is a division of powers between church and state.
Among those attending will be Camilla, Charles's wife of 17 years who now has the title of Queen Consort, and the King's son, William, the new Prince of Wales.
The first public proclamation is due to take place from the Friar Court balcony of St James's Palace in London at 11:00, a moment that is usually accompanied by centuries-old pageantry, with trumpeters playing a fanfare and gun salutes fired in Hyde Park and at the Tower of London.
Following the first, a second Proclamation will be read in the City of London at the Royal Exchange around midday on the same day as the first Proclamation. Further Proclamations will be read in Scotland, Northern Ireland, and Wales at midday on September 11.
The Accession Council must take place before Parliament meets, and Parliament should meet as soon as practicable after the death of a sovereign.
At 1 am, Parliament will hold a second day of Tributes to the Queen.
King Charles on Friday pledged to follow his "darling mama's" life of service in an emotional first address.
The King promised to serve the nation with the same "unswerving devotion" as the late Queen had during her 70-year reign.
On Friday, Charles was met by cheers and shouts of "God save the King!" as he met people in the crowds who had gathered at Buckingham Palace.