Charles III is the new British King

A statement from His Majesty The King:

A statement from His Majesty The King: pic.twitter.com/AnBiyZCher

— The Royal Family (@RoyalFamily) September 8, 2022

Tanjug/AP Photo/Kirsty Wigglesworth

At the moment the Queen died, the throne passed immediately and without ceremony to the heir, Charles, the former Prince of Wales.
But there are a number of practical - and traditional - steps which he must go through to be crowned King.
He will be known as King Charles III.
That was the first decision of the new king's reign. He could have chosen from any of his four names - Charles Philip Arthur George.
In the first 24 hours or so after his mother's death, Charles will be officially proclaimed King.
There is no "swearing in" at the start of a British monarch's reign, in the style of some other heads of state. But there is a declaration made by the new King and - in line with a tradition dating from the early 18th Century - he will make an oath to preserve the Church of Scotland.
Afterwards, a public proclamation will be made declaring Charles as the new King. This will be made from a balcony above Friary Court in St James's Palace.
Gun salutes will be fired in Hyde Park, the Tower of London and from naval ships, and the proclamation announcing Charles as the King will be read in in Edinburgh, Cardiff and Belfast.
First in line to the throne is now Charles' eldest son Prince William, who along with his wife Kate, are the most prominent representatives for the family.