The British King Charles III. will be officially proclaimed king in a ceremony on Saturday, a day after vowing to emulate his “favorite mama”, Queen Elizabeth II, in his first speech to mourning subjects.

The 73-year-old automatically became monarch after the Queen’s death on Thursday, but a Council of Accession ceremony at St James’s Palace early Saturday is a constitutional formality to recognize his sovereignty.

With trumpets and a balcony proclamation, the pompous protocol is the final part of a 10-day official mourning program – which will be even longer for the royals – being held across Britain ahead of the Queen’s funeral.

An emotional Charles set the tone for his reign in a televised address on Friday, in which he hailed his mother’s “unwavering devotion” during her record-breaking seven decades on the throne.

“Queen Elizabeth was a life well lived, a promise her fate kept and her passing is deeply mourned. I renew that promise of a lifetime of service to all of you today,” he said.

The new king also named his elder son and next heir Prince William, 40, as the new Prince of Wales while expressing his love for his younger son Harry and daughter-in-law Meghan.

The move means William’s wife Kate will inherit the title of Princess of Wales once held by his mother and Charles’ ex-wife, the late Princess Diana.

Crowds have gathered outside Buckingham Palace to mourn the Queen and wish Charles well. Some of them chanted “God Save the King” as he greeted them on Friday’s return from Scotland.

As the oldest monarch to ascend the British throne, he received flowers, cheers and even kisses after traveling from the Balmoral retreat, where his 96-year-old mother passed away peacefully.

Earlier, church bells and ceremonial gun salutes rang out for the late monarch across the UK as it tried to come to terms with the death of the only monarch most have ever known.

Charles is officially proclaimed King by the Accession Council, which consists of other royal, political and religious figures including Queen Consort Camilla, Prince William, Prime Minister Liz Truss and the Archbishop of Canterbury.

The centuries-old process will be televised for the first time.

The council will initially meet without Charles at 10:00 (0900 GMT) at St James’s Palace to proclaim him. Then he will join him to make a formal declaration as king and sign official documents.

The ‘Principal Proclamation’ will be read to the public at 11am from a balcony at St James’s Palace – which is close to Buckingham Palace – after a fanfare by three trumpeters.

It will then also be read in Scotland, Northern Ireland and Wales.

When Charles’ recorded address was broadcast to the nation, dignitaries attended a memorial service for his mother at St. Paul’s Cathedral, where the updated national anthem, “God Save the King,” was officially performed for the first time.

“Suddenly you feel like he’s his own person,” said Barbara Lewis, a pensioner from west London, who was among several hundred mourners outside the cathedral.

The new king’s adult life was overshadowed by his mother’s record-breaking reign, which spanned a period of extraordinary change in Britain and around the world.

Her death has drawn heartfelt tributes from all parts of the world.

Buckingham Palace announced that Charles and other members of the royal family would observe an extended mourning period from now until seven days after their funeral.

The date of the funeral, which leaders will attend, has yet to be officially announced but is expected to take place on Monday September 19.

US President Joe Biden has announced his participation. The Kremlin said Russian President Vladimir Putin will not do so.

Her London palace has become a magnet for thousands of mourners, with flowers piling up in one of the many poignant tokens of sincere reverence for her.

“She’s been our monarch my whole life,” said Joan Russell, a 55-year-old project manager from north-east London, tears streaming down her cheeks.

Truss – appointed by the late monarch on Tuesday – led two days of tributes to the Queen in Parliament and offered Charles the nation’s support as she acknowledged the “magnificent responsibility” that now rests on him.

While the government has said organizations are not required to cease trading during their 10-day mourning period, many are doing so out of respect.

The English Premier League has postponed all games this weekend while railway and postal workers halted forthcoming pay strikes amid rising inflation and soaring energy prices sweeping Britain.

The Queen’s death comes as the government scrambles to pass emergency legislation to address the kind of war-related economic deprivation that marked the beginning of her reign in 1952.

Elizabeth’s public appearances had dwindled in the months since she spent an unscheduled night in hospital in October 2021.

Though she was smiling, she was visibly thinner and flexed in her final official photos Tuesday appointing Truss.

The new leader was the 15th prime minister of her reign, which began with Winston Churchill in 1952.

Elizabeth’s body is expected to remain at Balmoral before being taken to the Palace of Holyroodhouse in Edinburgh on Sunday.

From the Scottish capital, her coffin is due to travel to London on Tuesday to rest there for several days.

Officials expect more than a million people will pass by the catafalque at Westminster Hall, the oldest part of Britain’s Parliament complex, ahead of the televised funeral service at Westminster Abbey across the street.

The funeral will be a public holiday in the form of a memorial day.

The coronation of Charles, an elaborate ritual steeped in tradition and history, will take place on a date to be determined in the same historic setting as it has for centuries.

Queen Elizabeth II ascended the throne aged just 25 in a depraved post-war world dominated by political figures from Churchill to Mao Zedong and Joseph Stalin.

In the decades that followed, the last remnants of the vast British empire crumbled, while at home Brexit shook the very foundations of their kingdom.

Her family endured a series of scandals and the death of Diana in a car accident in Paris in 1997, to which she was initially thought to have had a poor reaction.

But she remained popular throughout, and was head of state not just for the UK but for 14 former British colonies, including Australia and Canada.