4 Infantry Battalion AMF (Australian Rifles) 8th Brigade 5th Division

About This Unit

4th Infantry Battalion, AMF (WW2 Militia)

When the Second World War began the Australian government decided to raise an all volunteer force for overseas service. This force was known as the Second Australian Imperial Force (2nd AIF).

The militia was retained to build up defensive capability in Australia because there were concerns that Britain's capacity to defend Singapore might be compromised, if the Japanese were to enter the war; particularly so after Dunkirk in May 1940.

With its WW1 antecedence still felt keenly, the 4th Battalion (militia) was a ready source of trained manpower, as were all of the other militia Battalions.

As a result, initially there was a cap placed on the number of militiamen who were able to join the 2nd AIF. Nevertheless, large numbers of militiamen did volunteer for service and in an effort to preserve the territorial identity of the pre-war militia units, many men from the 4th Battalion were allocated to the 2nd/4th Battalion, AIF, which was raised at Ingleburn, New South Wales, in October 1939.

In January 1940, the compulsory training scheme (and a draft of males of elgible age) which had been suspended since 1929 was reintroduced and militia units were progressively called up for three month periods of full-time service in order to improve their readiness in case they were to be called upon to fight.

The militia was explicitly intended, by Law, for the defence of Australia and its Territories exclusively, at least initially.

The 4th Battalion (Australian Rifles) was mobilised in early 1942 following Japan's entry into the war and in June 1942 they concentrated at Greta, in the New South Wales Hunter Valley, and with the 30th and 35th Battalions, formed the 8th Brigade.

In July they were moved to Western Australia where they remained for the next two years, carrying out various garrison duties such as training, building and manning defensive positions and providing a labour force, located at various sites along the coast between Bunbury and Geraldton, forming part of the 2nd Division.

During this period, on 15 March 1943,  the Battalion suffered a large number of fatal casualties in a training accident, when a mortar bomb exploded in the course of a lecture, killing 14 soldiers.  See the link in the sidebar.

Fig 1. The funeral of the 14 soldiers killed in the training accident on 15 March 1943, at Moora War Cemetery.  After the war the soldiers remains were relocated to the Perth War Cemetery.

At the end of 1943 the 8th Brigade was moved to North Queensland and shortly afterwards in January 1944, it was reallocated to the 5th Division and deployed to New Guinea.  The 4th Battalion was the first of the 8th Brigade units to arrive and relieved the 2nd/17th Battalion at Sio.  Thereafter it began the task of clearing the coast between Sio to Saidor, in order to support the 9th Division's campaign on the Huon Peninsula.

In early February, they had completed this objective and were relieved by the 30th Battalion at Crossingtown.  As the campaign progressed the 8th Brigade was tasked with clearing the Madang–Bagadjim area and the 4th Battalion carried out patrols between the Maclay River and Bostrem Bay.

In May, the brigade went on the offensive against the Japanese forces located to the north of Alexishafen in order to support the 6th Division's campaign in the Aitape–Wewak region. In mid June, the 4th Battalion took over the advance and occupied Bogia, Potsdam and Hansa Bay.  In October, following the end of hostilities, they were moved to Wewak as the demobilisation process began. The last members of the battalion departed for Australia on 24 January 1946 and the battalion was subsequently disbanded.

In the course of its WW2 duties the Battalion suffered 39 casualties, of whom 15 were killed. Members of the battalion were awarded two Military Medals and six Mentions in Despatches.


After the war the 4th Battalion was incorporated into the CMF, initially merged with the 3rd Battalion.  In 1965 it regained its own identity as the 4th Batallion the Royal New Soth Wales Regiment, an arrangment that persisted until 1987, when it was remerged as the senior (and largest) partner in the 4/3 RNSWR, in which form it persists at the time of writing

Compiled by Steve Larkins Aug 2020   (a member of A Coy & Spt Coy 4RNSWR 1972-75)


Unit History AWM https://www.awm.gov.au/collection/U56084 accessed 17 August 2020