On 6 August 1914, at the outbreak of the First World War, Australia agreed to a request by the British government to seize German wireless stations in German New Guinea.

Australia was also required to occupy the territory under the British flag and establish a military administration. The Australian Naval and Military Expeditionary Force (AN&MEF) was formed for this.

The Expeditionary Force landed at Rabaul on 11 September 1914, took possession of German New Guinea at Toma on 17 September 1914 and the neighbouring islands of the Bismarck Archipelago in October 1914.