The Territory of New Guinea was an Australian-administered 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. 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 Japan during World War II, between 1942 and 1945. During this time, Rabaul, on the island of New Britain, became a major Japanese base (see New Guinea campaign). After World War II, the territories of Papua and New Guinea were combined in an administrative union under the Papua New Guinea Provisional Administration Act (1945–46). Background In 1884, Germany formally took possession of the northeast quarter of New Guinea and it became known as German New Guinea. In the same year, the British government proclaimed a protectorate over the southeastern quarter of New Guinea. The protectorate, called British New Guinea, was annexed by Britain outright on 4 September 1888. The territory was transferred to the newly federated Commonwealth of Australia on 18 March 1902, and British New Guinea became the Territory of Papua, with Australian administration beginning in 1906. World War I to League of Nations mandate One of the first actions of Australia's armed forces during World War I was the seizure by the Australian Naval and Military Expeditionary Force of German New Guinea and the neighbouring islands of the Bismarck Archipelago in October 1914. Germany administered several territories in the south and central Pacific which the British requested be captured by Australian and New Zealand forces. On 11 September 1914, a Royal Australian Navy force arrived off Rabaul with the Australian Naval and Military Expeditionary Force and naval troops were landed at Herbertshohe and Kabakaul to search for German radio stations, facing some minor German resistance. Rabaul was