4th Division (Australia)

4th Division
4th Division troops at Le Verguier, France, September 1918
Active	1916–1919 1921–1944
Country	Australia
Branch	Australian Army
Type	Division
Part of	II ANZAC Corps (1916) I ANZAC Corps (1916–1917) Australian Corps (1917–1919) 3rd Military District (Inter-war years) III Corps (World War II)
Engagements	World War I Western Front World War II Home front
Commanders
Notable commanders	Herbert Cox William Holmes Ewen Sinclair-Maclagan
Insignia
Unit colour patch

The Australian 4th Division was formed in the First World War during the expansion of the Australian Imperial Force (AIF) infantry brigades in February 1916. In addition to the experienced 4th Brigade (previously in the original New Zealand and Australian Division) were added the new 12th and 13th Brigades (spawned from the battalions of the 4th and 3rd Brigades respectively). From Egypt the division was sent to France, where it took part in the fighting on the Western Front during 1916–1918. After the war ended, the AIF was demobilised and the division was dissolved.

In 1921, the 4th Division was reactivated as a Citizen Military Forces (militia/reserve) formation. The division performed home defence duties for most of World War II. The division's composition during World War II changed frequently, as brigades were rotated between different divisions and moved to different locations as the need arose. The division spent the majority of the war in Western Australia, before moving to Queensland prior to its deactivation in late 1944.