King Charles III vows 'lifelong service' as crowds mourn queen

King Charles III pledged to follow his mother's example of "lifelong service" in his inaugural address to Britain and the Commonwealth, after ascending to the throne following the death of Queen Elizabeth II.

Speaking for the first time as monarch from Buckingham Palace, the 73-year-old thanked his "darling mama" for her "love and devotion to our family and to the family of nations".

"May flights of angels sing thee to thy rest," Charles, wearing a black suit and tie, said in an emotional address -- in a quote from Hamlet.

"As the queen herself did with such unswerving devotion, I too now solemnly pledge myself, throughout the remaining time God grants me, to uphold the constitutional principles at the heart of our nation."

Earlier, the oldest heir to ascend to the throne received flowers, cheers and even kisses as he greeted well-wishers outside Buckingham Palace on his return from Scotland, where his mother died "peacefully" aged 96.

Church bells and ceremonial gun salutes for the departed monarch had sounded across a country dealing with the loss of a constant presence for the last 70 years.

Charles -- who held his first audience with British Prime Minister Liz Truss as monarch -- will be formally proclaimed king to the public.

In his address, he said his elder son William, who moves up the line of succession to become heir, would become the new Prince of Wales.