King Charles III: Edinburgh Castle fires Royal salute as King Charles III is declared monarch

Members of the 105th Regiment Royal Artillery fired the cannons at the castle ramparts to welcome the new king.

The nation’s new monarch has been formally declared head of state at St James’ Palace in London on Saturday (September 10).

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The Royal Salute is fired at Edinburgh Castle by 105th Regiment Royal Artillery to mark the Principal Proclamation of King Charles III, in Edinburgh (Photo by ODD ANDERSEN/AFP via Getty Images)

The historic ceremony took place during a meeting of the Accession Council attended by privy councillors and aired on television for the first time.

Following tradition, the new King was missing from proceedings and did not witness senior figures from national life including the Queen consort, the new Prince of Wales and the Prime Minister taking part in the ceremony.

Broadcast cameras were allowed into the historic event giving the world a first glimpse of an ancient ceremony dating back centuries – and one of the first changes to convention instigated by the new King.

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.

King Charles III speaks during a meeting of the Accession Council inside St James's Palace in London to proclaim him as the new King (Photo by VICTORIA JONES/POOL/AFP via Getty Images)

The new monarch became King the moment his mother died, but an Accession Council must be convened following the death of a sovereign, usually within 24 hours.

Queen Elizabeth II died on Thursday (September 8) at Balmoral Castle in Aberdeenshire. Her coffin is to be taken to Edinburgh where there will be a procession from the Palace of Holyroodhouse, up the Royal Mile to St Giles’ Cathedral, where she will lie in state.

King Charles III also confirmed there is to be a Bank Holiday in England, Wales, and Northern Ireland for the day of the Queen’s state funeral, which is expected to take place on Monday, September 19, in London.

In a speech following the death of the Queen, the former Prince of Wales said: “It is the greatest consolation to me to know of the sympathy expressed by so many to my sister and brothers and that such overwhelming affection and support should be extended to our whole family in our loss.

"My mother's reign was unequalled in its duration, its dedication and its devotion. Even as we grieve, we give thanks for this most faithful life."

Additional reporting by PA.