King Charles III has been officially proclaimed as the ruling monarch of Australia by Governor-General David Hurley.
"Because of the death of our blessed and glorious Queen Elizabeth II, the Crown has solely and rightfully come to Prince Charles Philip Arthur George," General Hurley proclaimed.
"May King Charles III have long and happy years to reign over us.
"With hearty and humble affection, we promise him faith and faithfulness."
The proclamation was signed by General Hurley and countersigned by Prime Minister Anthony Albanese.
The flags were raised to fly at full-mast as the Australian Army Band Corps played its first rendition of God Save the King in more than 70 years.
The Governor-General was welcomed with a smoking ceremony and welcome to country by Ngunnawal elder Aunty Violet Sheridan before the Australian national anthem was played.
"No matter what your views, Queen Elizabeth lived a life of service, and she also was also a loving wife, mother, grandmother and great-grandmother ," Aunty Violet said.
"King Charles III takes over from his mother and we know he will be thoughtful in his rule."
At Government House, where the Prime Minister and the Federal Executive Council recommended the proclamation of King Charles III be made, General Hurley said today was the dawn of a new era.
"Australia is an unfinished product, and is now entering a new era," General Hurley told the council.
"Your loyalty to our King and your service to Australia through your work in the parliament will assist our country to build on the successes of the second Elizabethan age."
Anthony Albanese told the council the first proclamation of a new monarch in his lifetime, and in the lifetimes of most Australians, "is an historic event".
The flag will return to half-mast at dusk, where it will remain until the day after the Queen's funeral.
This evening, Australia's high commissioner to the United Kingdom will attend a reception with the King and other Commonwealth high commissioners.
Later in the week, the Prime Minister and Governor-General will fly to England, where they will meet King Charles III.
Earlier this morning, Mr Albanese told the ABC that a national day of mourning to occur the day after he returns from the Queen's funeral in London will be made a one-off public holiday.
