Terminology of Military Units – Part 1: Infantry Formations, Divisional Level and Below

Battalion: a fundamental unit of 600 to 1000 men, usually in 3 or 4 companies, commanded by a lieutenant colonel. Again most of the companies in the battalion will be ordinary infantry companies, but there will often be one support weapon company with machine guns and mortars. In the infantry, the battalion is usually the smallest unit that will be sent to the theatre of war – an infantry battalion would be sent abroad as a whole, rather than sending some of its companies.

Regiment: anything from 1 to 4 battalions. In some armies, regiments are combat formations that are usually kept together. In the British Army the regiment is an administrative unit and its battalions (if it even has more than one) might be serving in different countries. In the British Army, the regiment is the focus of a soldier’s sense of belonging, and the traditions and battle honours belong to the regiment as a whole.

Brigade: a unit of several battalions or regiments (depending on whether the structure includes regiments as a separate level). This is the point where we start to get into large operational units (maybe around 5,000 strong), led by a general (a brigadier general), and with headquarters that are capable of planning sustained operations. It is also the level at which units from other services start to be attached. A brigade might have its own artillery attached, for example. If other combat units, such as armour (tanks) are attached then it might be termed a brigade battlegroup.

Division:until the advent of the brigade battlegroup this was the lowest all-arms formation and in the case of all-out war the basic operational unit that would be sent into the theatre of war. By all-arms I mean that an infantry division would have artillery as a permanent part of its structure, along with reconnaissance units in armoured cars or light tanks. Main battle tanks, however, are usually concentrated in specialised armoured divisions for launching the main punch attacks, with infantry divisions forming the backbone of an army. There can also be specialised airborne divisions of paratroopers. It is also at the divisional level that various support services appear in significant numbers: the medical services, the signallers, and even postal units – everything that is needed to keep a group of men that can be up to 20,000 strong functioning. When you think that this is the size of a small town, but a nomadic town that can be expected to be shifted to another part of the world at short notice and still function, you can begin to imagine the sort of support services that are needed.

In the British Army, the division is the highest level that currently exists. Only when the army is swollen by called-up reservists and conscripts are there enough men together at one time to make larger operational units like corps, armies and even army groups necessary, formations I will discuss in a later part. And if the above seemed a bit dry, I’m going to give examples of some famous and less famous formations to bring them to life and illustrate the terminology in action.

Links to other parts of this series:

Part 2: higher level formations: http://socyberty.com/military/terminology-of-military-units-part-2-high-level-formations/

Part 3: tank and artillery units: http://socyberty.com/history/terminology-of-military-units-part-3-tank-and-artillery-units/