The Territory of New Guinea was an Australian-administered League of Nations and then United Nations trust territory on the island of New Guinea from 1914 until 1975. In 1949, the Territory and the Territory of Papua were established in an administrative union by the name of the Territory of Papua and New Guinea. That administrative union was renamed as Papua New Guinea in 1971. Notwithstanding that it was part of an administrative union, the Territory of New Guinea at all times retained a distinct legal status and identity until the advent of the Independent State of Papua New Guinea.

Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the centre, tropical rainforests in the north-east, tropical savannas in the north, and mountain ranges in the south-east.