Charles became king immediately upon the death of his mother, Queen Elizabeth II, on Thursday. He was officially proclaimed King Charles III on Saturday during a ceremony at St James's Palace in London, and many more formal steps will follow until his coronation, which may not come for months. A look at the centuries-old traditions and rules surrounding the accession of a new British monarch:

Who formally declares new monarchs?

In Britain, the death of a sovereign and their successor is officially proclaimed by the Accession Council, formed of a large group of senior politicians and officials.
Traditionally, the council is summoned within 24 hours of a monarch’s death for a ceremonial meeting at St James’s Palace. But the accession ceremony for King Charles III was delayed because the queen’s death wasn't announced until early evening on Thursday, and there was not enough time to set the plans in motion for Friday. The Accession Council is formed of members of the Privy Council, mostly past and present politicians, including all living prime ministers, as well as Church of England leaders and senior royals, and other ceremonial leaders, such as the Lord Mayor of London.