Charles III is set to be formally proclaimed king at a historic ceremony at St James's Palace on Saturday as flags were lowered in mourning for Queen Elizabeth II who passed away on Thursday at the age of 96. The flags will fly full-mast after the Accession Council meet, BBC reported.
The ceremony, which comes after the King pledged to follow his "darling mama's" life of service in an emotional first address on Friday, will be televised for the first time.
Charles set the tone for his reign hailing his mother's "unswerving devotion" during her record-breaking seven-decade reign.
Watch: Outpouring of love and grief in Britain for Queen Elizabeth II
"Queen Elizabeth's was a life well lived, a promise with destiny kept, and she is mourned most deeply in her passing. That promise of lifelong service I renew to you all today," he said.
King Charles III, 73, automatically became the monarch upon the queen's death, but an Accession Council ceremony at St James's Palace is a constitutional formality to recognize his sovereignty.
In his address, the new king also named his elder son and next heir Prince William as the new Prince of Wales, while expressing love for his younger son Harry.
{{/usCountry}}In his address, the new king also named his elder son and next heir Prince William as the new Prince of Wales, while expressing love for his younger son Harry.
{{/usCountry}}Read more: Explained: Queen's state funeral will be UK's first since Winston Churchill
William's wife Kate assumes the Princess of Wales title once held by Charles' ex-wife, the late Princess Diana.
Britain has declared a period of mourning until the state funeral for Elizabeth, the date for that has not been announced. Leaders from around the world are expected to attend the funeral in London.