4th Battalion (Australia)

4th Battalion, AIF 4th Battalion (Australian Rifles) 4th Battalion, Royal New South Wales Regiment
Battalion headquarters, Sio, New Guinea, January 1944
Active	1914–1919 1921–1930 1937–1946 1957–1960 1965–1987
Country	Australia
Branch	Australian Army
Type	Infantry
Size	~800–1,000 officers and men
Part of	1st Brigade, 1st Division (First World War) 8th Brigade, 5th Division (Second World War)
Motto(s)	Nomine Quartus
Colours	White over green
Engagements	First World War Gallipoli campaign Western Front Second World War Huon Peninsula campaign Aitape–Wewak campaign
Commanders
Notable commanders	Iven Giffard Mackay
Insignia
Unit colour patch
Abbreviation	4 RNSWR

The 4th Battalion was an infantry battalion of the Australian Army. Originally raised as part of the First Australian Imperial Force during the First World War, the battalion formed part of the 1st Brigade, attached to the 1st Division. During the war the battalion fought at Gallipoli and in the trenches on the Western Front, before being disbanded in 1919.^[1] In 1921, the battalion was re-raised as a militia unit and designated as the "4th Battalion (Australian Rifles)",^[2] adopting the designation of the Australian Rifles militia unit from which many of the battalion's recruits had come during the war. In 1930, the battalion was amalgamated with the 3rd Battalion (Werriwa Regiment) and they remained linked until 1936, when they were delinked.^[3]

During the Second World War, the 4th Battalion formed part of the 8th Brigade. Initially the battalion was used as garrison troops in Australia, serving in Western Australia, in early 1944 they were deployed to New Guinea as part of the 5th Division, where they participated in the Huon Peninsula and Aitape–Wewak campaigns, before returning to Australia in early 1946 and were subsequently disbanded.

In 1957, the battalion was re-raised as part of the Citizens Military Force, perpetuating the battle honours of the previously existing units that had fought during the First and Second World Wars.^[4] In 1960, with the introduction of the Pentropic organisation into the Australian Army and the subsequent formation of the Royal New South Wales Regiment the battalion was absorbed into the 3rd Battalion, Royal New South Wales Regiment, forming that unit's 'D' and 'E' Companies.^[4] In 1965, the battalion was reformed as the "4th Battalion, Royal New South Wales Regiment" and it remained in existence until 1987 when it was once again amalgamated with the 3rd Battalion to form the 4th/3rd Battalion, Royal New South Wales Regiment, a unit which remains in existence today.