Territory of New Guinea in the context of "Papua Act 1905"

The Territory of Papua comprised the southeastern quarter of the island of New Guinea from 1883 to 1975. In 1883, the Government of Queensland annexed this territory for the British Empire. The United Kingdom Government refused to ratify the annexation but in 1884 a protectorate was proclaimed over the territory, then called British New Guinea. There is a certain ambiguity about the exact date on which the entire territory was annexed by the British. The Papua Act 1905 recites that this happened "on or about" 4 September 1888. On 18 March 1902, the Territory was placed under the authority of the Commonwealth of Australia. Resolutions of acceptance were passed by the Commonwealth Parliament, which accepted the territory under the name of Papua.

In 1949, the Territory and the Territory of New Guinea 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 Papua at all times retained a distinct legal status and identity; it was a Possession of the Crown, whereas the Territory of New Guinea was initially a League of Nations mandate territory and subsequently a United Nations trust territory. This legal and political distinction remained until the advent of the Independent State of Papua New Guinea in 1975.

The New Guinea campaign of the Pacific War lasted from January 1942 until the end of the war in August 1945. During the initial phase in early 1942, the Empire of Japan invaded the Territory of New Guinea on 23 January and Territory of Papua on 21 July and overran western New Guinea (part of the Netherlands East Indies) beginning on 29 March. During the second phase, lasting from late 1942 until the Japanese surrender, the Allies—consisting primarily of Australian forces—cleared the Japanese first from Papua, then New Guinea, and finally from the Dutch colony.

The campaign resulted in a crushing defeat and heavy losses for the Empire of Japan. As in most Pacific War campaigns, disease and starvation claimed more Japanese lives than enemy action. Most Japanese troops never even came into contact with Allied forces and were instead simply cut off and subjected to an effective blockade by Allied naval forces. Garrisons were effectively besieged and denied shipments of food and medical supplies, and as a result, some researchers claim that 97% of Japanese deaths in this campaign were from non-combat causes. According to John Laffin, the campaign "was arguably the most arduous fought by any Allied troops during World War II."

The Papua and New Guinea Act 1949 was an Act passed by the Parliament of Australia. It replaced the Papua Act 1905 and the New Guinea Act 1920, and changed the status of the territories of Papua and New Guinea by merging their administrations to form Papua and New Guinea. The Act established local rule, although the territory remained under control by Australia. The Act was repealed by the Papua New Guinea Independence Act 1975 which allowed for Papua New Guinea's independence from Australia.

South West Pacific Area (SWPA) was the name given to the Allied supreme military command in the South West Pacific Theatre of World War II. It was one of four major Allied commands in the Pacific War. SWPA included the Philippines, Borneo, the Dutch East Indies (excluding Sumatra), East Timor, Australia, the Territories of Papua and New Guinea, and the western part of the Solomon Islands. It primarily consisted of United States and Australian forces, although Dutch, Filipino, British, and other Allied forces also served in the SWPA.

The Pacific Ocean theater of World War II was a major theater of the Pacific War, the war between the Allies and the Empire of Japan. It included the U.S. Pacific Ocean Areas command, which comprised most of the Pacific Ocean and its islands.

The Philippines, Dutch East Indies, British Borneo, Australia, most of the Territory of New Guinea, and the western Solomons were under a different Allied command.

The South West Pacific theatre, during World War II, was a major theatre of the war between the Allies and the Axis. It included the Philippines, the Dutch East Indies (except for Sumatra), Borneo, Australia, its mandate Territory of New Guinea (including the Bismarck Archipelago) and the Solomon Islands' western part. This area was defined by the Allied powers' South West Pacific Area (SWPA) command.

Japanese forces fought primarily against the United States and Australian forces in the South West Pacific theatre. The Philippines, New Zealand, the Netherlands (in the Dutch East Indies), the United Kingdom, and other Allied nations also contributed forces.

The Territory of Papua and New Guinea was established by an administrative union between the Australian-administered territories of Papua and New Guinea (the latter being a United Nations trust territory administered by Australia) in 1949. In December 1971, the name of the Territory changed to "Papua New Guinea" and in 1975 it became the Independent State of Papua New Guinea.