Whilst the Constitution of the Commonwealth of Australia came into effect on 1 January 1901, this did not mean that Australia had achieved independence from Britain.
Under colonial federation approved by the United Kingdom, the six self-governing states of Australia merely allocated some functions to a federal authority.
Australia was given the status of a Dominion, remaining a self-governing colony within the British Empire, with the Head of State being the British monarch.
The Governor-General and State Governors were appointed by the British government, and answered completely to the British government.
At the Imperial Conference of 1926, it was decreed that all Dominions within the British Empire were “equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown, and freely associated as members of the British Commonwealth of Nations.”
The Statute of Westminster 1931 ratified the discussions of the Imperial Conference.
It meant that Australia and other Dominions such as South Africa, New Zealand and Canada could now conduct treaties and agreements with foreign powers, and manage their own military strategies.
Ultimately, the British monarch could only act on the advice of the Australian Government, and the Governor-General was no longer appointed by and answerable to the British monarch.
Australian Parliament formally adopted the Statute of Westminster 1931 under the Statute of Westminster Adoption Act 1942, on 9 October 1942.