Structure of Australia's forces in World War I


The structure of Australia's military force changed over the course of the war. At the outbreak of war, Australia had a small navy and a small regular army. Part-time volunteers in the Citizen Forces were unable to serve overseas. Thousands of men enlisted in the armed forces when recruiting began.

Forces for wartime service

Australia responded quickly to the early telegram warnings from the United Kingdom (UK), by:

  • placing Australian ships under British control
  • recruiting volunteers to serve in the armed forces overseas
  • mobilising a volunteer unit to occupy German New Guinea

The Royal Australian Navy (RAN) was placed under the command of the British Admiralty almost immediately.

General Sir William Bridges was instructed to raise an Australian military force to serve in Europe. Building on a defence scheme that he created in 1908, Bridges wanted Australian troops to fight together, separate from the British army units.

Military organisation

Bridges was appointed to command the Australian Imperial Force (AIF) in August 1914.

With Chief of Military Staff, Lieutenant-Colonel Sir Cyril Brudenell White, Bridges planned the Order of Battle for the AIF. Initially, they aimed to:

  • recruit members of the citizen army and men with experience in militia units and rifle clubs
  • form military units with territorial connections, with men drawn from the same regions

The infantry battalions and light horse regiments recruited men from their own states throughout the war. Only specialty units, such as the artillery, medical corps and engineers, drew men from all over Australia.

Order of Battle

At the start of the war, the military structure included 12 battalions organised into 3 brigades within 1 division. The structure was similar to Lord Kitchener's defence scheme for Britain.

1st Division

1st Infantry Brigade

Supplied by New South Wales (NSW):

2nd Infantry Brigade

Supplied by Victoria:

3rd Infantry Brigade

Supplied by the least populous states of Australia:

Later in the war, the 2nd, 3rd and 5th Australian Divisions each contained one brigade from NSW, one from Victoria and one from the other four states. In the 3rd Australian Division, the Tasmanian battalion was in the Victorian brigade.

Military organisation of combat forces




Commanded by


60,000 people or more

2 corps or more



30,000 people or more

2 divisions or more

Lieutenant General


10,000 to 20,000 people

3 brigades

Major General


2500 to 4000 people

4 battalions



550 to 1000 people

4 companies

Lieutenant Colonel


100 to 225 people

4 platoons

Major or Captain


30 to 60 people

4 sections



9 to 16 people

Sergeant or Corporal

Towards the end of the war, some Australian battalions were so depleted of men through injury, illness and loss that they were lucky to have enough people for a full-strength company.

The 4th and 8th Infantry Brigades were exceptions to the general system. They each contained units of men from all the Australian states because less populous states could not field enough complete battalions.

Capturing a territorial spirit

To create a strong bond within each unit, recruitment offices tried to recruit men and officers from the same region, not just from the same state.

The units were to be connected with the different States in Australia; they were to be definitely local and territorial.

[Charles Bean, 1935]

For example, the brigadier of 1st Infantry Brigade allotted the 13th, 14th, 15th, 16th, 17th, 18th, 19th and 20th training areas to the 2nd Battalion. These areas were in the northern parts of NSW. The men of 2nd Battalion were mostly drawn from the coal fields of NSW, and its first two commanding officers came from that area too.

The Australian Military Forces continued with the recruitment directives first designed by Bridges. But action later in the war affected these plans. For example, the Australian 6th Division was only briefly in existence. After tragic casualties at the Battle of Bullecourt in 1917, the division broke up to reinforce the surviving divisions.

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DVA (Department of Veterans' Affairs) ( ), Structure of Australia's forces in World War I, DVA Anzac Portal, accessed 25 June 2024,
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