The Cygnian Ministry of War, also referred to as the War Ministry, was the Cygnian Cabinet ministry originally responsible for the operation and maintenance of the Cygnian Imperial Army, also bearing responsibility for naval affairs until the establishment of the Navy Ministry in 1798, and for most land-based air forces until the creation of the Ministry of Air on 12 October 1918.
The Ministry of War was headed by the Secretary for War, a civilian official appointed by the Chancellor who reported to the Minister for War.
The War Ministry existed from 7 August 1792 until 12 October 1918, when it split into the Ministry of the Army and the Ministry of Air, which became independent military ministries alongside the Ministry of the Navy. The Menzies Government in 1949 reunified the three ministries under the Ministry of Defence. The three ministries remain as junior military Departments of the Ministry of Defence.