Britain's new monarch will be known as King Charles III

Clarence House confirmed on Thursday that Britain's new monarch will be known as King Charles III, after the death of his mother Queen Elizabeth.

Charles succeeds his mother, who was Britain's longest-reigning monarch and the nation's figurehead for seven decades.

Queen Elizabeth II died on Thursday afternoon at Balmoral Castle in Scotland. She was 96.

Charles automatically assumed the throne after news of his mother's death but will be declared the new monarch only on Friday, according to reports.

This will reportedly take place at a meeting of the Accession Council, which usually gathers at St James's Palace in London, according to Daily Mail.

The Duke of Cambridge, Prince William, will become the heir apparent, while his three children princes George, Louis and princess Charlotte will move up the succession line. Prince Harry will become fifth in line, followed by Archie and Lilibet, named for the queen.

Charles, in his first act as new king, released a statement on Thursday evening, mourning the death of his “beloved” mother and “cherished sovereign”. 

“I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world,” he said.

The queen's death comes more than a year since the death of Charles's father, Prince Philip, who died at Windsor Castle at the age of 99.

-Additional reporting by Reuters