Australia's Governor-General will today officially proclaim King Charles III, the first new monarch in 70 years, Australia's new Head of State.
David Hurley will make the proclamation at Parliament House in Canberra as part of a formal half-hour ceremony.
The official acknowledgement of the change of monarch follows the United Kingdom proclamation at the Accession Council at the State Apartments of St James's Palace, in London on Saturday night Australian time.
Further proclamations will be read in Scotland, Northern Ireland and Wales on Sunday.
Other Commonwealth nations and Australians states will read separate proclamations.
Sunday's ceremony will be the first time a proclamation has been read at Australia's current Parliament House.
The ceremony will include a band performing the Australian anthem and God Save the King, a version of the British national anthem not heard for 70 years.
There will also be a Welcome to Country and Indigenous spiritual dance before the ceremony concludes with a 21-gun salute at 12:30pm AEST.
The national flag will temporarily be flown at full mast before being lowered to half mast in mourning of Queen Elizabeth II who died on Thursday, aged 96.
First proclamation in 70 years
The Australian proclamation of Queen Elizabeth II took place at Canberra's Old Parliament House
The governor-general at the time, Sir William John McKell, read out that proclamation on February 8, 1952.
That reading took place 16 years after the Queen's father King George VI ascended to the thrown when his brother abdicated.
Australia has had 14 governors-general since the Queen was proclaimed.
Queen Elizabeth II made 16 visits to Australia during her 70-year reign.
Her son and heir King Charles III has already accrued the same number, including in 1966, when he was sent out to Timbertop — the famously rugged rural campus of Geelong Grammar School for two terms.
Day two of commemorations
The late monarch had a special fondness for Australia, a respect to be honoured with more than a week of ceremony after her passing.
Canberra's most prominent landmark has been lit up with projections of Queen Elizabeth II.
There have been several rotations of pictures and words displayed at the front of the building.
One displays a message in the late monarch's own words: "Australia in the course of my lifetime has firmly established itself amongst the most respected nations of the world."
On Saturday politicians and diplomats laid wreaths at the foot of a statue of the Queen, unveiled by Her Majesty in 1988.