During this time the division's composition changed numerous times as many of its subordinate units were transferred. Shortly after mobilisation the division lost its engineer field companies and in June 1940 the three artillery regiments assigned to the division were also transferred out, to be replaced by a light horse regiment which had been converted to the machine gun role although this too was later removed from the division's order of battle. In mid-1942, the division's headquarters staff were transferred along with their commander, Major General Cyril Clowes, to Milne Force, which later took part in the Battle of Milne Bay. Later the division was transferred to the Second Army. By April 1943, the division consisted of the 1st, 9th and 28th Brigades, and was headquartered in Parramatta. As manpower restrictions in the Australian economy forced the early demobilisation of large numbers of men, the majority of which came from infantry units in Australia that were not involved in fighting overseas. The 1st Division was one of these units and by January 1945, when the 2nd Brigade was disbanded, the division consisted of only one infantry brigade, the 1st. The division was officially disbanded on 6 April 1945.