The former Prince of Wales became King Charles III immediately upon the death of Queen Elizabeth II on Sept. 8, but on Sept. 10, he was formally declared head of state. (AP)
Guards march during the proclamation of Britain’s King Charles III, following the passing of Britain’s Queen Elizabeth II. (AP)
Police detain a man who was running towards St James's Palace on The Mall shortly before King Charles III arrived at Buckingham Palace after the official Proclamation of Accession took place in St James's Palace, September 10, 2022. King Charles III became the head of the British Monarchy due to the passing of Her Majesty Queen Elizabeth II on September 8th 2022 at the age of 96. (Hugo Michiels/Shutterstock)
Police tackle a man who was running towards St James's Palace on The Mall shortly before King Charles III arrived at Buckingham Palace after the official Proclamation of Accession took place in St James's Palace, September 10, 2022. King Charles III became the head of the British Monarchy due to the passing of Her Majesty Queen Elizabeth II on September 8th 2022 at the age of 96. (Newsline Media/MEGA for Fox News Digital)
A tribute to Queen Elizabeth II was displayed on the iconic Piccadilly Circus billboards on September 8, after the monarch’s death was announced. (AP)
Catherine, Princess of Wales, Prince William, Prince of Wales, Prince Harry, Duke of Sussex, and Meghan, Duchess of Sussex, on the long Walk at Windsor Castle on Sept. 10, 2022, meet and greet with well-wishers. (Getty Images)
The Prince and Princess of Wales and The Duke and Duchess of Sussex view the tributes left after the Death of Queen Elizabeth II, at Windsor Castle, Windsor, Berkshire, UK, on the 10th September 2022. (Getty Images)
Princess Catherine and Prince William greet people outside of Windsor Castle on Sept. 10, 2022. (Getty Images)
Prince William, Prince of Wales, greets people outside Windsor Castle on Saturday, September 10, 2022. (Newsline Media/MEGA for Fox News Digital)
The Prince and Princess of Wales view the tributes left after the Death of Queen Elizabeth II, at Windsor Castle, Windsor, Berkshire, UK, on the 10th September 2022. 10 Sep 2022 Pictured: The Prince and Princess of Wales view the tributes left after the Death of Queen Elizabeth II, at Windsor Castle, Windsor, Berkshire, UK, on the 10th September 2022. (Fox News Digital)
Meghan, Duchess of Sussex, greet people outside of Windsor Castle on Sept. 10, 2022. (Getty Images)
The Prince and Princess of Wales and The Duke and Duchess of Sussex view the tributes left after the Death of Queen Elizabeth II, at Windsor Castle, Windsor, Berkshire, UK, on the 10th September 2022. 10 Sep 2022 Pictured: The Prince and Princess of Wales and The Duke and Duchess of Sussex view the tributes left after the Death of Queen Elizabeth II, at Windsor Castle, Windsor, Berkshire, UK, on the 10th September 2022. (Fox News Digital)
Members of the Royal family visit Crathie Kirk for a private service then do a walkabout speaking to members of the public who came to lay flowers and pay respects for Queen Elizabeth II who died on Thursday. 10 Sep 2022 Pictured: Members of the Royal family visit Crathie Kirk for a private service then do a walkabout speaking to members of the public who came to lay flowers and pay respects for Queen Elizabeth II who died on Thursday. (Newsline Media/MEGA for Fox News Digital)
Lady Louise Windsor, Sophie, Countess of Wessex, Prince Andrew, Duke of York, Prince Edward, Earl of Wessex, Anne, Princess Royal, and Timothy Laurence pay respects at Windsor Castle on September 10, 2022. (Getty Images)