Formation At the outbreak of the Second World War, the Australian government decided to raise the
Second Australian Imperial Force, an all volunteer force for overseas service that was separate to the previously existing part-time
Militia. Initially, this force consisted of a single
division – the
6th Infantry Division – as well as some base and support troops. On 25 February 1940, the decision was made to expand the 2nd AIF to a
corps, consisting of two infantry divisions – the 6th and
7th – and throughout March and into April work began to start forming the new units, and establish a corps headquarters, in
Melbourne. This formation would be responsible for the AIF units forming in Australia. On 11 April 1940, the establishment of I Corps was gazetted, and by the middle of the month the headquarters' strength was reported as 12
officers and 45
other ranks. Lieutenant General
Thomas Blamey was appointed General Officer Commanding (GOC). In late May 1940, approval was provided for the 2nd AIF to raise a third division – the
8th – although it would ultimately not serve with I Corps. Preparations also commenced for I Corps headquarters personnel to begin moving overseas. A small rear corps headquarters was to remain in Australia, although the responsibility for command of troops in Australia would be devolved to the 7th Division until it also deployed. The initial deployment of staff began in May, but the majority of draft made it only as far as
Fremantle, Western Australia, before disembarking and returning to Melbourne, when the decision was made to divert this convoy to the United Kingdom, rather than the main corps-area in the Middle East. The personnel who reached the UK were subsequently used to form
HQ Australforce. Meanwhile, the main element of the corps headquarters, including Blamey, reached
Palestine in mid-June 1940. They arrived amidst fighting in the
Western Desert, and it was considered that the AIF troops could soon be committed to battle.
Mediterranean and Middle Eastern theatres Initially, when I Corps headquarters arrived there was only one Australian infantry division in the Middle East – the 6th, which was completing its training – however between October and December the 7th arrived, followed by the
9th by January 1941. During this time, the brigades assigned to each division were shuffled between superior headquarters as a result of several reorganisations to provide the better trained brigades to the formations likely to see combat first. At this time, the main elements of the corps headquarters moved forward towards the combat zone, leaving the administrative staff in
Gaza and establishing themselves in
Ikingi Maryut, in Egypt. Here they began preparations for operations. The 6th Infantry Division was the first to go into action,
capturing Bardia in early January 1941. This was followed by further actions at Tobruk, Derna, Barce, and Benghazi, as the Italians were forced to withdraw across Libya by the Allies. In February, I Corps took over control of
Cyrenaica in
Libya, replacing the
British XIII Corps, and briefly adopting the designation of HQ Cyrenaica Force. This deployment lasted only a month, before I Corps headquarters was withdrawn back to Egypt to prepare for deployment to
Greece for the
campaign there, which began in April 1941. Initially, it had been planned for the 7th Division to deploy to Greece, but they were not considered fully trained, and as a result the 6th Division was dispatched. In their place, the newly arrived 9th Division replaced the 6th Division in the Western Desert, and they would subsequently take part in the
Siege of Tobruk in mid- to late- 1941 when the Axis forces counter-attacked in the Western Desert. Meanwhile, in Greece, the corps controlled the Australian 6th Division, the
New Zealand 2nd Division, and the
British 1st Armoured Brigade, as well as several ad hoc forces charged with the defence of northern Greece. On 12 April, it was officially renamed the
Anzac Corps, a reference to the combined Australian-New Zealand formations of
World War I. This was short-lived, though, as the Allied forces in Greece were quickly overcome by the
German advance and after withdrawing from
Gerania through
Elasson,
Larissa and
Levadia, I Corps HQ left Greece on 23–24 April, and were subsequently evacuated to Egypt, although elements of the 6th Division were landed on
Crete where they fought another short and
unsuccessful campaign in May. The corps re-formed in
Deir Suneid, in Palestine, during which time the previous I Corps designation was assumed. In June 1941, as part of the initial plan for the
invasion of Lebanon and Syria, held by
Vichy French forces, I Corps was to take command of operations after
Commonwealth forces reached their first objective, the
Beirut–
Damascus road. However, on 18 June, prior to that objective being reached, I Corps headquarters – based at
Nazareth – took charge, to improve command and control of the Allied forces. From this date all Allied troops in the theatre came under the command of Lieutenant General
John Lavarack, who took over from Blamey when he became deputy commander-in-chief in the Middle East. The forces under I Corps' command around this time included: 7th Division (less the
18th Infantry Brigade), the
British 6th Infantry Division, the
1st (Free French) Light Division and the
5th Indian Infantry Brigade Group. The corps directed operations that captured
Damascus and
Damour before the armistice took effect on 12 July. Following the armistice in July, I Corps headquarters was established at
Aley, near Beirut, and assumed responsibility for occupying all of Lebanon and Syria north of the Beirut–Damascus road. Eventually, the Australian 6th Infantry Division arrived to relieve the British 6th.
Pacific area Java, Ceylon, and home defence Following the outbreak of the
Pacific War, I Corps headquarters, along with the 6th and 7th Divisions, were released from service in the Middle East to meet the threat posed by the Japanese advance through the Pacific. The divisions departed Egypt by sea in several convoys between January and March 1942. The 9th Division would remain in the Middle East, though, upon request, and would see further action in the
First and
Second Battles of El Alamein, where they would be assigned to the
British XXX Corps. As the situation in the Pacific grew desperate for the Allies, plans were made to deploy I Corps headquarters, and the 6th and 7th Divisions, to
Sumatra,
Java, or possibly to
Burma to help stem the tide of the Japanese advance on
Rangoon. An advanced party, including the corps commander, Lavarack, flew to Java ahead of the landing and advised against deploying the force there, advising that they should be sent to Burma instead. The Australian government ultimately rejected the request to divert the 7th Division to Rangoon, and although most of the force returned to Australia, Lavarack was not able to prevent some elements from landing in Java – mainly the troops on the transport
Orcades consisting of a machine gun battalion (the
2/3rd) and a pioneer battalion (the
2/2nd), as well as engineers, transport and medical personnel, who became part of Blackforce under Brigadier
Arthur Blackburn. This force fought briefly alongside US and Dutch forces before being overwhelmed and taken into captivity. I Corps HQ was subsequently relocated to Australia, reaching
Adelaide in March 1942 and then moving to Melbourne. The 7th Division deployed to northern New South Wales, while the 6th Division (less the
19th Infantry Brigade which was sent to garrison Darwin) was detached to
Ceylon to provide a garrison to defend against a possible Japanese invasion. The invasion did not eventuate, and the Australians remained on the island until July 1942, and finally reached Australia the following month. While the 16th and 17th Brigades were in Ceylon, the Army in Australia had undergone a significant reorganisation to meet the threat of a possible Japanese invasion. In April 1942, I Corps headquarters was used to raise an army level formation, the
First Army, and a new I Corps headquarters was raised from Headquarters Southern Command (previously the
3rd Military District. I Corps came under the command of Lieutenant General
Sydney Rowell around this time. Assigned to the defence of southern Queensland, the new I Corps moved to
Esk, Queensland, where it became part of the First Army and commanded troops in northern New South Wales and Queensland, including the 25th Infantry Brigade, the Brisbane Covering Force, the 7th Infantry Brigade, the 1st Motor Brigade and the remainder of the 7th Division, which was held back in reserve around
Glen Innes, New South Wales. In this assignment, it joined
II Corps, one of the two other corps (the other being
III Corps) raised at this time. In May 1942, the corps was bolstered with the remainder of the
3rd Infantry Division, although they were transferred to II Corps in July, and moved further north, and were replaced within I Corps by the US
32nd Infantry Division.
New Guinea As the fighting in New Guinea intensified and the Japanese advanced beyond
Kokoda, plans were made to reinforce the troops along the
Kokoda Track. As a result, in August 1942, I Corps headquarters deployed to
Port Moresby where they took over from the existing headquarters
New Guinea Force, becoming Headquarters I Corps & New Guinea Force, although for all intents and purposes it was referred to as New Guinea Force. The formation subsequently commanded the troops around Milne Bay, which subsequently
repulsed a Japanese landing, as well as the 7th Division troops deploying along the Track, the 6th Division troops around Port Moresby, and
Kanga Force around
Wau. In late September, following the
withdrawal from Ioribaiwa Blamey decided to replace Rowell as corps commander with Lieutenant General
Edmund Herring, who had previously commanded II Corps. In October and November, the Japanese began to withdraw and the Australians – with elements from both the 6th and 7th Divisions – undertook counter-offensive that saw them reoccupy Kokoda, and then advance north towards the Japanese beachheads around
Buna and Gona. These beachheads were eventually captured in December 1942 and January 1943 by Australian and US forces from the 7th and 32nd Infantry Divisions, after heavy fighting. During this time, between November 1942 and January 1943, New Guinea Force deployed an advanced headquarters forward to control the fighting. Following the capture of northern Papua, New Guinea Force was reorganised, and new formations began arriving. Meanwhile, throughout the first half of 1943, Australian operations focused upon the
capture of Salamaua, which saw a series of battles aimed at securing Salamaua prior to
the drive on Lae. In August 1943, a new I Corps headquarters was raised from the New Guinea Force headquarters staff, and the corps headquarters established itself at Dobdura, where it was assigned to New Guinea Force as an army-level headquarters. Assigned the role of capturing Lae, I Corps was provided with the 7th Infantry Division, which in early September 1943 was flown in to Nadzab and attacked overland from there and the 9th Infantry Division, which carried out and amphibious landing to the east of Lae, before assaulting along the coast. Lae was captured more quickly than had been expected, and later in the month, this was followed up by elements of the 9th Division which carried out a
landing at Scarlet Beach, as part of operations to
secure the Huon Peninsula, while the 7th Division began operations to
secure the Markham and Ramu Valleys. The following month, however, I Corps headquarters was relieved by II Corps, as its personnel were in need of rest, and they subsequently returned to Australia. II Corps and New Guinea Force would subsequently command the conclusion of the operations commenced by I Corps, culminating in the
capture of Madang in April 1944. Meanwhile, in Australia, I Corps headquarters was re-established at
Barrine, Queensland, where it took command of units resting and training prior to their commitment for further operations. At this time, the corps was assigned the 3rd and 6th Infantry Divisions, based at
Kairi and
Wondecla respectively. In early 1944, the corps was also assigned the 9th Infantry Division, at
Ravenshoe, following its return from New Guinea for rest. In February 1944, Herring retired and command of I Corps temporarily passed to Lieutenant General
Stanley Savige. In April 1944, I Corps headquarters provided individual staff reinforcements for the II Corps headquarters, although there was no name change at this time, and I Corps remained in Australia in order to command the 2nd AIF divisions, while II Corps took over the deployed Militia divisions: the 3rd, 5th and 11th. As a result, Lieutenant General
Frank Berryman assumed command of I Corps. In line with this, the 7th Infantry Division was transferred to I Corps at this time as they returned from New Guinea for rest, although they were based further south than the other elements, around
Strathpine. Meanwhile, the 3rd Infantry Division re-deployed to New Guinea, and the 7th Infantry Division moved to Kairi, to concentrate nearer to the other I Corps formations.
Borneo Throughout 1944, plans were made for I Corps to be used in the Philippines and Ambon, but ultimately these were not acted upon as the role of Australian forces in the Pacific diminished and as US forces gained the ascendency. By October 1944, Lieutenant General
Leslie Morshead had assumed command of the corps. Finally, it was decided that the force would be committed to the operation to
re-take Borneo in mid-1945, in order to secure important air and naval bases to allow further operations elsewhere in Borneo and then later Java. For the operation, the corps was placed directly under General
Douglas MacArthur's
command, rather than being assigned to the US
Eighth Army. Advanced elements of I Corps headquarters subsequently moved to
Morotai Island in March 1945, followed by the remainder of the headquarters the following month. From there, they directed a series of amphibious landings that were carried out by the 7th and 9th Divisions at
Tarakan,
North Borneo and
Balikpapan through May, June and July. In all locations, the objectives were captured, albeit against stronger-than-expected resistance in some cases, with commensurately heavy casualties, after which the Australians pushed further inland, carrying out mopping up operations. On Tarakan, the airfield was captured five days after the landing, but it was badly damaged and ultimately filled no role in subsequent operations. Meanwhile, in North Borneo, after operations to secure Labuan and Brunei had proved successful, a follow-up landing was made around Weston, with a subsequent advance towards Beaufort, which was captured after heavy engagement resulted in over 100 Japanese killed. By mid-July, the main resistance around Balkipapan and the coastal areas had been overcome, and the defending Japanese had withdrawn into the hills further inland. Following the cessation of hostilities in August, the corps assumed responsibility for facilitating the Japanese surrender on Borneo and in making preparations for returning the area to Dutch colonial control in the post war period. This included undertaking local and protective patrols to maintain law and order and to secure Japanese soldiers who had not yet surrendered. As part of the
demobilisation process, I Corps headquarters closed on 15 September 1945, at which time its constituent divisions were transferred to the direct command of Advanced Land Headquarters. In the post war period, no corps-level formations have been raised by the Australian Army. ==Subordinate formations==