On 1 January 1901, federation of the colonies was achieved after a decade of planning, constitutional conventions and referendums, resulting in the establishment of the Commonwealth of Australia as a nation and the entering into force of the Australian Constitution.[90]
After the 1907 Imperial Conference, Australia and several other self-governing British settler colonies were given the status of self-governing "dominions" within the British Empire.[91][92] Australia was one of the founding members of the League of Nations in 1920,[93] and subsequently of the United Nations in 1945.[94] Britain's Statute of Westminster 1931 formally ended most of the constitutional links between Australia and the United Kingdom. Australia adopted it in 1942,[95] but it was backdated to 1939 to confirm the validity of legislation passed by the Australian Parliament during World War II.[96][97]
The Federal Capital Territory (later renamed the Australian Capital Territory) was formed in 1911 as the location for the future federal capital of Canberra. Melbourne was the temporary seat of government from 1901 to 1927 while Canberra was being constructed.[98] The Northern Territory was transferred from the control of the South Australian government to the federal parliament in 1911.[99] Australia became the colonial ruler of the Territory of Papua (which had initially been annexed by Queensland in 1883)[100] in 1902 and of the Territory of New Guinea (formerly German New Guinea) in 1920. The two were unified as the Territory of Papua and New Guinea in 1949 and gained independence from Australia in 1975.[101][102][103]