King Charles III leaves Balmoral Castle to address nation from London

Britain's new king prepared to meet with the prime minister and address a nation mourning Queen Elizabeth II

Britain's new king prepared to meet with the prime minister Friday and address a nation mourning Queen Elizabeth II, the only British monarch most of the world had known and a force of stability in a volatile age.

The country began a 10-day mourning period Friday, with bells tolling around Britain and 96-gun salutes planned in London one for each year of the queen's long life. People around the globe gathered at British embassies to pay homage to the queen, who died Thursday in Balmoral Castle in Scotland.

King Charles III, who spent much of his 73 years preparing for the role, takes the throne in an era of uncertainty for both his country and the monarchy itself. In Britain and across its former colonies, the widespread admiration for Elizabeth herself was sometimes mixed with criticism of the institution and the imperial history she represented.

On the king's first full day of duties Friday, he and his wife Camilla, the Queen Consort, left Balmoral to head to London. He is expected to meet Prime Minister Liz Truss, appointed just days earlier, and deliver a speech to the nation at a time when many Britons are preoccupied with an energy crisis, the soaring cost of living, the war in Ukraine and the fallout from Brexit.

Hundreds of people arrived through the night to leave flowers outside the gates of Buckingham Palace, the monarch's London home, or simply to pause and reflect.

Finance worker Giles Cudmore said the queen had just been a constant through everything, everything good and bad.

She's just been the foundation of my life, the country, he said.