The Department of the Army was created by Executive Council Minute 72, (Prime Minister's Department Minute Number 167) on 13 November 1939 (notified in Commonwealth of Australia Gazette, No 134, 14 November 1939, p 2391).
 
The first Minister for the Department of the Army was Brigadier the Honourable Geoffrey Austin Street, MC.   He had previously been Minister for Defence (Commonwealth Gazette, No 134, 14 November 1939, p 2391).  

The basic administrative and financial functions in relation to the Army were taken over by the new Department from the Department of Defence [II] (CA 19).  These include certain executive functions previously discharged by the Defence Secretariat, clerical work associated with the Military Board and the Branches of the Chief of General Staff, Adjutant-General, Quartermaster-General, and Master-General of Ordnance, the work of the Civil Staff of the Ordinance Branch and of the Inspection Staff engaged on the inspection functions of the Munitions Supply Branch and the Finance Branch (Military).
 
On 31 October 1941, War Cabinet decided upon the appointment of a Business Member to the Military Board.  He became Business Adviser in April 1942, and the Business Adviser's Branch was set up to assist him. The functions of the Business Adviser were to advise the Minister in regard to:
 
 Provision, inspection, custody, accounting and disposal of
  military stores, equipment and supplies;
 Workshop and Repair Establishments;
 Transport and Veterinary Services;
 Works and Buildings; and
 Any other matters affecting Army Administration.
 
On 30 October 1941, a Press Relations Section was established within the Department to prepare and facilitate the issue of statements to the Press, to act as a point of contact in the Department for the Minister's Press Relations Officer, and to maintain newspaper files.
 
In January 1942, the Army Accounting Advisory Panel (later known as the Finance and Accountancy Advisory Board) was established to advise the Minister on accounting systems in the Department.  The members of the Board acted in an honorary capacity.
 
On 19 March 1942, the Army Inventions Directorate was constituted by National Security (Army Inventions) Regulations, Statutory Rule 1942/178. It was to provide an organisation with service representatives, independent of the defence services, to consider and investigate:

 (a) all inventions, new devices and ideas submitted to the
     Directorate; and
 (b) scientific or technical problems in connection with the defence
     of the Commonwealth.
 
In September 1942, the Central Hirings Committee was constituted by the National Security (Hirings Administration) Regulations, Statutory Rule 1942/401, to control, facilitate and guide the exercise of the powers of the Commonwealth in respect to the hirings and acquisition of property for war purposes and to facilitate and expedite the assessment and payment of compensation.  The Railway Accounts Section was established at the same time to advise on the economics of transport and to check railway passenger and freight accounts with all State and Commonwealth Railways for the services.  The Section dealt with railway accounts for the RN, the RAN, the AMF, the RAAF, the US Navy, and Army, Service Canteens, Allied Works Council and Commonwealth Disposals Commission.  

During the War, particulary in 1942 and 1943, in pursuance of an approval given by the Minister for Defence in July 1940, many positions in various sections were been filled by military personnel.  This Ministerial approval did not cover the following sections:
 
 (a) Secretariat including staff section and registry;
 (b) Treasury Division of Finance Branch at LHQ;
 (c) Inspection Division of MGO's Branch; and
 (d) Censorship Branch.
 
Some military personnel were however, employed in the Treasury Division of the Finance Branch and in 1944 approval was given for the employment of military personnel in the main administrative positions in the Inspection Division.
 
The principal matter dealt with by the Department at the time of its creation was Military Defence.
 
The Commonwealth Directory 1972 (p 42), stated that at that date it was responsible for organization, training, administration and control of the Military Forces in accordance with the Defence Act 1903-1970 and the policy directed by the Minister.
 
The following legislation was administered by the Department at its creation:
 
 Australian Imperial Force Canteens Funds Act 1920
 Deceased Soldiers' Estates Act 1918-1919
 Defence Act 1903-1939 (in relation to the organization and control
  of the Military Forces
 (Commonwealth Gazette, No 153, 30 November 1939, p 2636).  

By 1972 it was responsible for the following legislation:
 
 Australian Imperial Forces Canteens Act 1920-1950
 Defence Act 1903-1970, in relation to the organization and control
  of the Military Forces
 Services Trust Funds Act 1947-1950 Part V
 War Precautions Act Repeal Act 1920-1966, other than paragraphs (c)
  and (f) of section 22, in relation to the Military Forces
 War Service estates Act 1942-1943, insofar as it applies to the  
  Military Forces
 (Commonwealth Gazette, No 131, 20 December 1972, p 2).
 
With the coming to power in December 1972 of the Australian Labor Party, the new Minister for the Army was the Honourable Lance Herbert Barnard MP.  He was also the Minister for Defence [III], Navy, Air and Supply. On 30 November 1973 the Department of the Army was abolished in pursuance of Section 64 of the Consitution and the Office of the Secretary to the Department of the Army was abolished in pursuance of the Public Service Act 1922-1973.  (Commonwealth Gazette, No 129, 19 December 1972, p 2; Australian Gazette, No 183, 30 November 1973, p 1).
 
This abolition was part of the amlgamation of the Armed Service Departments.  The Departments of Air, Army and Navy were merged with the existing Department of Defence [III] (CA 46) to form a single department.  The former Service departments became Offices within the Department of Defence, in this instance Army Office (CA 1568) and maintained the same functions.  The position of Permanent Head of the Department of the Army became Special Deputy of Permanent Head, Department of Defence (Army Office).  The administrative structure, activities and functions of the Department are subject to further research.
 
The following were Ministers for the Army:
 
13 Nov 1939 - 13 Aug 1940  : Hon Geoffrey Austin Street
14 Aug 1940 - 28 Oct 1940  : Senator the Hon Philip Albert Martin    
                             McBride 
28 Oct 1940 -  7 Oct 1941  : Hon Percy Claude Spender
 7 Oct 1941 -  1 Nov 1946  : Hon Francis Michael Forde (CP 81)
 1 Nov 1946 - 19 Dec 1949  : Hon Cyril Chambers
19 Dec 1949 -  7 Nov 1955  : Hon Josiah Francis
 7 Nov 1955 - 28 Feb 1956  : Hon Sir Eric John Harrison
28 Feb 1956 - 18 Dec 1963  : Hon John Oscar Cramer
18 Dec 1963 - 26 Jan 1966  : Hon Alexander James Forbes (CP 140)
26 Jan 1966 - 28 Feb 1968  : Hon John Malcolm Fraser (CP 51)
28 Feb 1968 - 12 Nov 1969  : Hon Phillip Lynch (CP 76)
12 Nov 1969 -  2 Feb 1972  : Hon Andrew Sharp Peacock (CP 234)
 2 Feb 1972 -  5 Dec 1972  : Hon Robert Cummin Katter
 5 Dec 1972 - 30 Nov 1973  : Hon Lance Herbert Barnard (CP 94)
 
Joseph Palmer Abbott acted as Minister assisting the Minister for the Army from 26 June 1941 to 29 August 1941.
Historical agency address
  1939-  1959: Victoria Barracks, St Kilda Road, Melbourne
by1950-by1967: Administrative Building, Canberra
by1967-by1973: Russell Offices, Canberra
Legislation administered
Creation: Executive Council Minute 72 Prime Minister minute No. 167 Minute of 13 November 1939
Abolition: Subject to further research