Specific field armies are usually named or numbered to distinguish them from "army" in the sense of an entire national defence force or land force. In
English, the typical
orthographic style for writing out the names of field armies is
word numbers, such as "First Army"; whereas corps are usually distinguished by
Roman numerals (e.g. I Corps) and subordinate formations with
ordinal numbers (e.g. 1st Division). A field army may be given a geographical name in addition to or as an alternative to a numerical name, such as the
British Army of the Rhine,
Army of the Potomac,
Army of the Niemen or
Aegean Army (also known as the Fourth Army). The
Roman army was among the first to feature a formal field army, in the sense of a very large,
combined arms formation, namely the , which may be translated literally as "sacred escort". The term is derived from their being commanded by
Roman emperors (who were regarded as sacred), when they acted as
field commanders. While the Roman (plural: ) is sometimes translated as "field army", it may also be translated as the more generic "field force" or "mobile force" (as opposed to or garrison units). In some armed forces, an "army" is or has been equivalent to a
corps-level unit. Prior to 1945, this was the case with a (; 'army') within the
Imperial Japanese Army, for which the formation equivalent in size to a field army was a (; 'area army'). In the
Soviet Red Army and the
Soviet Air Forces, an army was subordinate in wartime to a
front (an equivalent of
army group). It contained at least three to five
divisions along with artillery, air defense, reconnaissance and other supporting units. It could be classified as either a combined arms army (CAA) or tank army (TA); and while both were
combined arms formations, the former contained a larger number of
motorized rifle divisions while the latter contained a larger number of
tank divisions. In peacetime, a
Soviet army was usually subordinate to a
military district. Modern field armies are large formations which vary significantly between armed forces in size, composition, and scope of responsibility. For instance, within
NATO 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. NATO armies are commanded by a
general or
lieutenant general. ==See also==