The First Australian Army's headquarters was formed at
Toowoomba, Queensland, on 15 April 1942 when its headquarters was raised from the former Headquarters (HQ)
1st Australian Corps, which had been formed in January 1940 in Melbourne, before deploying to the Middle East with the
Second Australian Imperial Force. Under the command of Lieutenant General
John Lavarack, the formation subsumed the previous Northern and Eastern Commands, and was based in Queensland and New South Wales. Split into two corps – 1st and
2nd – initially the First Army had seven Australian divisions:
1st Infantry,
2nd Infantry,
3rd Infantry,
5th Infantry,
7th Infantry,
10th Infantry and
1st Motor. HQ First Australian Army controlled the 5th Infantry Division in
Townsville, Queensland, the new 1st Australian Corps (ex HQ
Southern Command) defending South Queensland, and 2nd Australian Corps (ex HQ
Eastern Command) defending New South Wales. When the 1st Australian Corps was sent to New Guinea in August 1942 and became known as
New Guinea Force, the 2nd Australian Corps moved to
Esk, Queensland, and New South Wales came under the
Second Australian Army. Two US infantry divisions – the
32nd and
41st – were also assigned to the First Australian Army for periods during this time, having been moved north and transferred from the Second Australian Army earlier in the year; nevertheless, these divisions were transferred to the US
I Corps from September 1942, and were increasingly divorced from the First Australian Army's control, with this separation being formalised in February 1943 when the US
Sixth Army headquarters was established in Brisbane. During 1942 and 1943, the units under the formation's command varied, and by August 1943, they controlled the
11th Brigade at
Merauke (Dutch New Guinea),
Torres Strait Force at
Thursday Island, the
4th Infantry Division at Townsville, the
3rd Armoured Division at
Murgon, and the 2nd Australian Corps on the
Atherton Tablelands, around Barrine, in Queensland. In late 1943, the First Australian Army consisted of 90,784 troops, with a further 41,871 personnel assigned to the Queensland line of communication area within the army's assigned boundary. These troops came under the First Army for operational purposes, but were administered separately by Land Headquarters. Upon formation, the First Australian Army's role had been focused on defending against a possible Japanese invasion, and assumed the main operational responsibility for this over the Second Army, which over time became focused mainly on training and lesser command roles. But as this threat subsided, a more offensive role developed for the First Army. In May 1944, HQ First Australian Army moved to
Mareeba, Queensland, to prepare for a more active role as Australian troops began relieving US troops in New Guinea to free them up for redeployment to the Philippines. While the main elements of the First Australian Army had been deployed forward to Mareeba, the formation had maintained a rear headquarters at
Chermside, Queensland. This headquarters administered several minor units in Brisbane until September 1944, when they came under the control of the Second Australian Army. At this time the army's rear headquarters rejoined headquarters main at Mareeba. In October 1944, the main element of the army's headquarters moved under Lieutenant General
Vernon Sturdee, to
Lae, in the Australian territory of
New Guinea, where it was tasked with undertaking operations across a broad area including
Bougainville,
New Britain and
Aitape. Here they controlled the 2nd Australian Corps on Bougainville, the 5th Infantry Division on New Britain, the
6th Infantry Division at Aitape and the
8th Infantry Brigade at
Madang. On Bougainville, New Britain and around Aitape, the Australians undertook limited offensive operations. This saw them secure the northern part of Bougainville up to the
Bonis Peninsula, and advance south on Bougainville towards the main Japanese strong hold around
Buin, while on New Britain they were able to establish a line across the base of the
Gazelle Peninsula, isolating
Rabaul. In northern New Guinea, they advanced from Aitape and by the end of the war had secured
Wewak. Meanwhile, a rear headquarters was left behind at Mareeba, where it assumed control of all forces not assigned for operations in the upcoming
Borneo Campaign, while the 1st Australian Corps was placed under direct command of Land Headquarters for the operation. The rear headquarters remained in existence until January 1945, when the
11th Division's headquarters assumed its duties. The HQ First Australian Army was disbanded in February 1946 when it was redesignated as the
8th Military District. ==Order of Battle==