The new King has expressed the “greatest sadness” in a written statement following the loss of his “beloved mother”.
Queen Elizabeth II died peacefully at Balmoral on Thursday afternoon (8 September) aged 96.
Charles acceded to the throne immediately on the death of his mother, who was the nation’s longest-reigning monarch, serving as head of state for more than 70 years.
‘The greatest sadness’
King Charles III spoke of his grief following the Queen’s passing and highlighted the “respect and deep affection” in which she was “so widely held”.
In a written statement, the new monarch said: “The death of my beloved mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family.
"We mourn profoundly the passing of a cherished Sovereign and a much-loved mother.
"I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world.
"During this period of mourning and change, my family and I will be comforted and sustained by our knowledge of the respect and deep affection in which The Queen was so widely held."
World leaders, celebrities and members of the public gathered at the gates of Buckingham Palace, Balmoral and Windsor Castle to pay tribute, with US president Joe Biden describing her as “a stateswoman of unmatched dignity”.
Prime Minister Liz Truss heralded the late monarch’s “great legacy” outside Downing Street as news of the end of the New Elizabethan era became a reality.
She said: “Queen Elizabeth II was the rock on which modern Britain was built. Our country has grown and flourished under her reign.
“Britain is the great country it is today because of her.”
King Charles III and his siblings had all travelled to be with the Queen at Balmoral in Scotland before her death was announced early on Thursday evening.
Royal doctors had recommended she remain under medical supervision, with the Palace issuing an unusually detailed update earlier in the day, saying medics were concerned for her health.
The Duchess of Sussex remained down south after initially planning to accompany Prince Harry to Scotland.
The Duchess of Cornwall and Cambridge, as Kate’s title is now, stayed in Windsor with her children Prince George, Princess Charlotte and Prince Louis, having had their first full day at school.
Charles to be formally proclaimed King at Accession Council
On Saturday morning, a historic Accession Council will meet at St James’s Palace in London on Saturday morning (10 September) to formally proclaim Charles as King.
The first public proclamation of the new sovereign will then be read in the open air from the Friary Court balcony at St James’s Palace by the Garter King of Arms.
Trumpeters usually play a fanfare from the balcony and gun salutes are fired in Hyde Park and at the Tower of London at the same time. The Proclamation will then be read at the Royal Exchange in the City of London.