Brigade was to embark for the Middle East in December 1941, with 2nd Armoured Brigade embarking in March 1942. These plans were, however, dropped in early December 1941 when it was decided to retain the division in Australia to defend against the feared Japanese landings on the Australian mainland. As an emergency measure the division's armoured regiments were equipped with Bren Carriers until sufficient tanks arrived. Major General Horace Robertson replaced Northcott in April 1942 when Northcott was promoted to command the newly established II Corps. The 1st Armoured Division's armoured regiments were equipped with M3 Grant medium tanks and M3 Stuart light tanks in April and May 1942. Following this, the division was concentrated in northern New South Wales where it completed its training with a series of large exercises around Narrabri. In January 1943, the division was moved to the area between Perth and Geraldton, Western Australia, where it formed part of III Corps to counter the perceived threat of a Japanese invasion of Western Australia. Disbandment Due to the end of the Japanese threat to Australia and the unsuitability of large armoured formations in jungle warfare the 1st Armoured Division no longer had any real role by 1943. By this time, there was a manpower shortage in the Australian Army, which required a re-allocation of personnel and the gradual reduction of Australia's armoured units. While the division was disbanded in September 1943, its 1st Armoured Brigade and other units was retained as the independent 1st Armoured Brigade Group. This brigade group unit remained part of III Corps in Western Australia until its disbandment in September 1944. The 4th Armoured Brigade, which was established in March 1943 and included several regiments which had previously formed part of the 1st Armoured Division, provided all the Australian armoured units which saw action from 1943 until the end of the war. Former elements in action While 1st Armoured Division never saw action as a complete formation, three regiments which were part of the division saw action in the South West Pacific Area, either while assigned to the division, or later. In September 1942, the 2/6th Armoured Regiment, equipped with M3 Stuart light tanks, was deployed to New Guinea, and subsequently saw action during the Battle of Buna–Gona. During 1944–1945, the 2/4th Armoured Regiment contributed squadron-sized elements to both the Bougainville campaign and Aitape–Wewak campaigns, equipped with Matilda tanks. The 2/9th Armoured