I Corps (Australia)

I Corps of the Australian Army was its main frontline corps during World War II. Various Australian and other Allied divisions came under its control at different times. In 1940–42, the corps was based in the Mediterranean Theatre. In 1942–45, it oversaw Allied frontline units in the South West Pacific Area.

The corps was established on 11 April 1940 in Melbourne to supervise the frontline divisions of the Second Australian Imperial Force (2nd AIF). Lieutenant General Thomas Blamey, the 2nd AIF commander, was appointed General Officer Commanding (GOC).

Mediterranean Theatre
Blamey left Australia to set up his headquarters in Palestine on 10 June 1940.

The corps took over control of Cyrenaica in Libya on 16 February 1941, replacing the British XIII Corps.

I Corps HQ was transferred to Greece for the campaign there in April 1941. The corps controlled the Australian 6th Division, the New Zealand 2nd Division, the Greek 12th Division and the British 1st Armoured Brigade. On 12 April, it was officially renamed the Anzac Corps, a reference to the combined Australian-New Zealand formations of World War I. (The Allied forces were quickly overcome by the German advance and I Corps HQ left Greece on 23–24 April).

In June, as part of the initial plan for the invasion of Lebanon and Syria, I Corps was to take command of operations after Commonwealth forces reached the Beirut-Damascus road. However, on 18 June 1941, prior to that objective being reached, I Corps 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. They included: the Australian 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. Following the hard-fought Allied victory, I Corps assumed responsibility for occupying all of Lebanon and Syria north of the Beirut-Damascus road, including the border with Turkey.

South West Pacific area
On 3 January 1942, following the outbreak of the Pacific War, the British government requested that two Australian divisions be sent to the Far East. The Australian government agreed to this request on 6 January, and ordered the redeployment of I Corps Headquarters, along with the 6th and 7th divisions. These formations had left Egypt for Java by the end of January.

Accompanying them were the two overseas regiments of 1 Australian Anti-Aircraft Brigade, namely the 1st Australian Light AA (Bofors) Regt and the 2nd Australian Heavy Anti-Aircraft (3.7") Regiment with their related Anti-Aircraft Signals Sections.

However, few Australian units had landed in the Netherlands East Indies before it had fallen to Japanese forces. There was a dispute between Winston Churchill and Australian Prime Minister John Curtin over whether the main part of the force should be sent to southern Asia or Australia. Nevertheless, I Corps HQ was relocated to Australia and the 6th Division (less the 19th Brigade) was detached to Ceylon, together with their complement of AA guns and Matador trucks.

Subordinate units
In the final stages of World War II, I Corps consisted of the following units:
 * 6th Division;
 * 7th Division;
 * 9th Division.

Commanders
The following officers served as commanding officer of I Corps:
 * 1940–41: Lt Gen Thomas Blamey
 * 1941–42: Lt Gen John Lavarack
 * 1942: Lt Gen Sydney Rowell
 * 1942–44: Lt Gen Edmund Herring
 * 1944: Lt Gen Stanley Savige
 * 1944: Lt Gen Frank Berryman
 * 1944–45: Lt Gen Leslie Morshead