Following the outbreak of the First World War, the New Zealand government authorised the formation of the New Zealand Expeditionary Force (NZEF), under the command of Major General Alexander Godley, for service abroad. By October 1914, there were sufficient volunteers to form two brigades, the New Zealand Infantry Brigade and the New Zealand Mounted Brigade. These two formations formed the main body of the NZEF and, together with the Australian 4th Infantry Brigade and the 1st Light Horse Brigade, were the basis of the New Zealand and Australian Division, which fought in the Gallipoli campaign against the Turks.
In December 1915, the much depleted New Zealand and Australian Division was evacuated from Gallipoli, and was placed in reserve near the Suez Canal. Although there were concerns that the Turks might attack the canal, it was envisaged that the division would soon be called upon to serve elsewhere. Commanded by Major General Andrew Hamilton Russell, it was replenished with reinforcements from Australia and New Zealand and began a program of intensive training.
Since the deployment of the main body of the NZEF, the numbers of volunteers had steadily increased to the point that they could no longer be integrated into either of the two existing brigades. In January 1916, the commander of the Mediterranean Expeditionary Force in Egypt, Lieutenant General Sir Archibald Murray, proposed the number of available New Zealand personnel warranted the establishment of two new brigades which, together with the existing brigade, would form a New Zealand infantry division for service on the Western Front. The New Zealand government, initially concerned by the prospect of maintaining three infantry brigades, concurred after Murray reassured it that the number of personnel in Egypt were sufficient to keep the new division up to strength in the short term.