Field army

A Field Army, usually referred to simply as an Army, is a term used by many national military forces for a formation superior to a corps and beneath an army group. Sometimes, we can name it Area Army, such as: the . A Field Army is composed of a headquarters, and usually controls at least two corps, beneath which are a variable number of divisions. A battle is influenced at the Field Army level by transferring divisions and reinforcements from one corps to another to increase the pressure on the enemy at a critical point. Armies are controlled by a General or Lieutenant General.

A particular army can be named or numbered to distinguish it from military land forces in general. For example, the First United States Army and the Army of Northern Virginia. In the British Army and United States Army, it is normal to spell out the ordinal number of an army (e.g. First Army), whereas corps use Roman numerals (e.g. III Corps) and lower formations use figures (e.g. 1st Division).

Armies (as well as army groups and theaters) are large formations which vary significantly between armed forces in size, composition, and scope of responsibility.

In the Soviet Red Army and the Soviet Air Force, "Armies" were actually corps-sized formations, subordinate to an Army Group-sized "front" in wartime. In peacetime, a Soviet army was usually subordinate to a military district.

Air Armies are an equivalent formation, in some air forces.

The distinguishing flag of a United States army is bicoloured, white over red, measuring 91.4 centemetres (36 inches) hoist by 121.9 centemetres (48 inches) fly, with gold fringe. In the center is a rendering of the army's shoulder-sleeve insignia, measuring 38.1 centemetres (15 inches) in height.

For the hierarchy of land forces organizations, see military organization.