[3] The Australian Naval and Military Expeditionary Force seized German New Guinea and the neighbouring islands of the Bismarck Archipelago for the Allies in 1914, during the early stages of the First World War.

"[5] Article 22 of the Treaty of Versailles provided for the division of Germany and the Central Powers' imperial possessions among the victorious Allies of World War I and German New Guinea, the Bismarck Archipelago and Nauru were assigned to Australia as League of Nations Mandates: territories "formerly governed [by the Central Powers] and which are inhabited by peoples not yet able to stand by themselves under the strenuous conditions of the modern world".

The offensives in Papua and New Guinea of 1943–44 were the single largest series of connected operations ever mounted by the Australian armed forces.

The economy was based on cash crops including coffee, cocoa, and copra as well as timber mills, wharves and factories.

The job of patrol officers involved: facilitating the consolidation of administrative influence, maintaining the rule of law, conducting court cases and presiding as Magistrate, carrying out police work, conducting censuses, encouraging economic development, providing escorts, purchasing land for governmental use and overseeing local elections.

1972 elections saw the formation of a ministry headed by Chief Minister Michael Somare, who pledged to lead PNG to self-government and then to independence.