King Charles III officially declared Britain's monarch in historic ceremony

Royal was accompanied by his wife Queen Consort Camilla and son Prince William at Accession Council ceremony

Queen Elizabeth II dies - follow the latest news as the world mourns

King Charles III has been officially proclaimed Britain's monarch in a historic Accession Council ceremony, which for the first time was broadcast live for viewers around the globe.

The king arrived at St James’s Palace, a royal residence in central London, on Saturday morning with his wife Queen Consort Camilla. He was also accompanied by his son Prince William, the new heir to the throne and bearer of his father's former title, Prince of Wales.

The UK's Accession Council met without the new king to proclaim him sovereign — officially confirming his title, King Charles III — before he joined them to make a series of oaths and declarations.

The Privy Council heard that Queen Elizabeth II died and that her eldest son had been proclaimed as King Charles III.

More than 200 privy councillors – a group of mostly senior politicians past and present, some members of the monarchy and other national figures – were present to hear the Clerk of the Council read the Accession Proclamation.

Prince William and the queen consort, both privy councillors, were among those who formally proclaimed King Charles III.

Prime Minister Liz Truss and Penny Mordaunt, leader of the House of Commons, in signing the declaration officially recognised him as king.

Several former prime ministers were also in attendance, including Boris Johnson, David Cameron, Theresa May and Tony Blair.

In an address after the proclamation was signed, the king paid tribute to his late mother.

He said it was his “most sorrowful duty” to announce the death of his mother and said the whole world sympathises with him “in the irreparable loss we’ve all suffered”.

He paid tribute to the outpouring of “overwhelming affection and support” to the royal family in the wake of the loss of their matriarch.

"My mother gave an example of lifelong love and of selfless service," he said. "My mother's reign was unequalled in its duration, dedication and devotion. Even as we grieve, we give thanks for this most faithful life. I am deeply aware of this deep inheritance and of the grave duties and responsibilities which are now passed to me."

He vowed to “strive to follow the inspiring example that has been set in upholding constitutional government and to seek the peace, harmony and prosperity of the peoples” across the UK and the Commonwealth realms.

He also acknowledged his spouse, saying: "I am profoundly encouraged by the constant support of my beloved wife."

With an eye on the road ahead at the helm of the royal family, he added: “I pray for the guidance and help of Almighty God”.

The king approved a bank holiday on the day of his mother's funeral.

After the ceremony, an official read the proclamation aloud from a balcony at St James’s Palace, watched by a crowd of members of the public. He proclaimed that "Prince Charles Philip Arthur George is now by the death of our late sovereign of happy memory become our only lawful and rightful liege lord, Charles III".

It will also be read out in the medieval City of London and at the Royal Exchange at noon.

God Save the King was performed by the Coldsteam Guard at St James's Palace while a gun salute took place at the Tower of London.

The ceremony is steeped in ancient tradition and political symbolism, and has garnered a high level of interest in the UK and abroad.

While Charles automatically became king when his mother died on Thursday at Balmoral, the Accession Ceremony is a key constitutional and ceremonial step in introducing the new monarch to the country.

Britain is holding a period of mourning for the queen, with days of carefully choreographed ceremonies marking the death of the only monarch most people have ever known.

In the next few days the queen’s body will be brought from Balmoral, first to Edinburgh and then to London, where she will lie in state before a funeral at Westminster Abbey, expected around September 19.