Territory of New Guinea

The Territory of New Guinea was an Australian-administered territory, first as a League of Nations mandate and then as a United Nations trust territory, in the northeastern part of the island of New Guinea and nearby islands, from 1914 until 1975. In 1949, it was united with the Territory of Papua to create 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.

The initial Australian mandate, entitled the Mandate for the German Possessions in the Pacific Ocean situated South of the Equator other than German Samoa and Nauru, was based on the previous German New Guinea, which had been captured and occupied by Australian forces during World War I.

Most of the Territory of New Guinea was occupied by Imperial Japan during the Pacific War, between 1942 and 1945. During this time, Rabaul, on the island of New Britain, became a major Japanese base (see New Guinea campaign). After the war, the territories of Papua and New Guinea were combined in an administrative union under the Papua New Guinea Provisional Administration Act (1945–46).