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Army (unit)

Military organization
Latvian platoon at Camp Lejune.jpg
Typical units Typical numbers Typical commander
fireteam 3–4 corporal
squad/
section
8–12 sergeant
platoon 15–30 lieutenant
company 80–150 captain/major
battalion/
cohort
300–800 lieutenant colonel
regiment/
brigade
2,000–4,000 colonel/
brigadier general
division/
legion
10,000–15,000 major general
corps 20,000–40,000 lieutenant general
field army 80,000+ general
army group 2+ field armies field marshal/
five-star general
region/
theater
4+ army groups Six-star rank/Head of state
Navies Armies Air forces
Commissioned and Non-commissioned officers
Admiral of
the fleet
Marshal or
Field marshal
Marshal of
the air force
Admiral General Air chief marshal
Vice admiral Lieutenant general Air marshal
Rear admiral Major general Air vice-marshal
Commodore Brigadier or
Brigadier general
Air commodore
Captain Colonel Group captain
Commander Lieutenant colonel Wing commander
Lieutenant
commander
Major or
Commandant
Squadron leader
Lieutenant Captain Flight lieutenant
Sub-lieutenant Lieutenant or
First lieutenant
Flying officer
Ensign Second lieutenant Pilot officer
Midshipman Officer cadet Flight cadet
Enlisted grades
Warrant officer or
Chief petty officer
Warrant officer or
Sergeant major
Warrant officer
Petty officer Sergeant Sergeant
Leading seaman Corporal Corporal
Seaman Private Aircraftman

A field army (or numbered army or simply army) is a military formation in many armed forces, composed of two or more corps and may be subordinate to an army group. Likewise, air armies are equivalent formation within some air forces. A field army is composed of 100,000 to 150,000 troops.

Particular field armies are usually named or numbered to distinguish them from "army" in the sense of an entire national land military force. In English, the typical style for naming 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 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 sacer comitatus, which may be translated literally as "sacred escort". The term is derived from the fact that they were commanded by Roman emperors (who were regarded as sacred), when they acted as field commanders. While the Roman comitatensis (plural: comitatenses) is sometimes translated as "field army", it may also be translated as the more generic "field force" or "mobile force" (as opposed to limitanei or garrison units).


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Wikipedia

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