Never having been in the military, I have trouble with these (and related) terms. How many soldiers are in each, and what rank would typically command each?
Platoon–Basic infantry unit, commanded by a second lieutenant and divided into squads headed by sergeants.
Company–Several platoons, commanded by a captain. In the cavalry (which in modern times means tanks), the equivalent unit is a troop; in the artillery, a battery.
Battalion–Several companies, commanded by a lieutenant colonel. The equivalent cavalry unit is a squadron.
Brigade–Several battalions, commanded by a colonel.
Division–Several brigades, commanded by a major general.
Corps–Several divisions, commanded by a lieutenant general.
Field Army–Several corps, commanded by a full general.
Regiments are no longer used by the U.S. Army, but traditionally were commanded IIRC by colonels (I think brigades were originally commanded by–duh–brigadier generals) and more or less fit in between brigades and battalions.
It depends what army you’re in, but typically, three of one thing makes another:
Three squads of 6-10 men make a platoon
Three platoons of 25-30 men make a company
Three companies of 100 men or so make a battalion
Three battalions make a regiment, now we’re at 1000 men or so
Three regiments make a brigade
Three brigades make a division - now we’re at 10000-20000 men
Three divisions make a corps
Three corps make an army
As you go up in force size, you’re adding on support functions; a mechanized infantry division will include three armored and/or infantry brigades, but it will ALSO include a divisional artillery regiment, a helicopter squadron, a field hospital, an MP company, an electronic warfare battalion, a transportation pool, etc. etc, all added on at the divisional level.
Bear in mind as well that when we start with “Squad” we’re assuming we’re talking about infantry. The rest of the army pretty much exists to support infantry, so that’s a good place to start.
The terminology does vary from army to army, though. In most armies, a brigade is typically commanded by a brigadier general - get it? One formation a lot of armies don’t have is a “corps” - some armies call their corps “armies.”
Lots of info in this thread.
MEBuckner
Actually, regiments are still used by the US Army. While Infantry units only use them for their regimental affiliation; ie. I was in Bravo Company, 5th Battalion of the 18th Infantry Regiment(Spartans) (B Co. 5/18 Inf), 3rd Brigade (Thunder), 3rd Armor Division (Spearhead).
However there are Armored Cavalry Regiments (ACR), which are basically reinforced brigades (their support units belong to the ACR rather than being attached as they are in brigades). Check out the 3rd ACR or the 7th ACR (I think those are the only active ACRs right now in the Army).
I believe the Marine Corp Expeditionary units are also considered to be regiments.
Oops, I should mention that MEBuckner is correct that tradionaly regiments where smaller than brigades.
Xgemina - Do cavalry units have their own special structure?
IIRC
battalian sized unit of cavalry = squadron
company = troop (ie F Troop)
Also, do other country’s have a similar structure?
Check here for various rank equivalents in the US/British Armed Forces.
This information is on a Finnish website. I hope they haven’t been spying on us. :eek:
msmith537
That’s pretty much how it is – not really a special structure, but different terminology for the same thing.
However, it really depends on whether the cavalry unit in question is a real cav unit or not.
Let’s take 3rd BDE 1st Cavalry Division for example. The 1st Cav is basically an infantry divison with delusions of being cavalry. Grey Wolf (3rd BDE) is made up of 3 “cavalry” units: the 1/9, 2/7, and 3/8 Cav. 1/9 and 2/7 Cav are really infantry battalions and 3/8 Cav is actually an armour battalion even though they are designated as cavalry. Actually 1/9 Cav was 3/41 Inf when I first arrived in 3BDE and was redesignated. Therefore all of these units are called battalions with subunits of companies. Most units that have a cav designation will be like this.
The 3rd ACR (Brave Rifles) OTOH is a real cav unit. It has 5 (4 line and 1 support) squadrons and it’s subunits are troops. The 3rd is made up of armor and scout units and as such has far fewer soldiers per troops than infantry battalions.
Hope this makes sense.
Duh, teach me not to use preview…
This should say fewer soldiers per troops than infantry companies. The same goes for squadrons and infantry battalions.
msmith357: “Also, do other country’s have a similar structure?”
Well, pretty well all armies organise at the levels described above, but where battalion (c. 1000) and regiment (c. 3000) level units are concerned, they use different terminology. Or rather, they use the same terminology for different things!..
E.g. the Argentine army uses “Regiment” for battalion-sized units.
E.g. the British army appears to does this for some of its units, by abbreviating, for example, “The First battalion of the Parachute Regiment” to “The First Parachute Regiment”.
Not sure whether there’s a wee bit of disinformation in this - i.e. making your enemies believe you have 100 regiment-sized units when you actually only have 100 battalion-sized units.
Basically it’s all very muddy, there’s no standardisation, and the whole thing feels very pre-ISO. 
I’m not sure that the British Army normally abbreviate names like that, jinty, but you’re right that there are certainly regiments. Unfortunately it’s a bit complex.
Infantry
In Britain the unit designations depend on the service (infantry, armour, artillery, engineers and so on). In the infantry, we have:
Section
Platoon
Company
Battalion (of a Regiment; see below)
Brigade
Division
Corps
Army (not since World War II)
Army Group (not since World War II)
Regiments are purely ceremonial ‘holding’ units for battalions, providing a shared identity and history. For example, The Parachute Regiment never fights as such, but it is ‘parent’ to several battalions that take their name from it - e.g. 1st Battalion The Parachute Regiment. Standard infantry units follow the same rules - e.g. 1st Battalion King’s Own Scottish Borderers. These names are general shortened to numeral and acronym/abbreviation - e.g. 3 Para or 2 KOSB.
Armour
Armour units are made up as follows:
Troop
Squadron
Regiment
(Brigade, Division etc)
Hence, an armoured regiment is equivalent in size to an infantry battalion, and fights as a single regiment of squadrons (i.e. company equivalents). The name indicates the fact it’s a coherent unit - e.g. 1st Royal Tank Regiment.
SAS
The SAS operates the same as armour. IIRC, even the unit names are the same. So, for example, you’d have 22nd Special Air Service Regiment. Of course, SAS units fight as small patrols, not as entire massed ranks.
Support arms
Support arms units (such as artillery or engineers) manage to confuse things further by combining both methods. You’ll have a number of regiments-the actual operational kind-with a ceremonial parent unit also called a regiment. So, for example, you’ll get 16 Fd Regt RA, which is short for 16th Field Regiment of the Royal Regiment of Artillery (Royal Artillery or RA for short). Regiments in artillery and air defence are made up of batteries rather than squadrons.
There are dozens of Royal Regiments of support arms - the Royal Artillery (RA), the Royal Horse Artillery (RHA), Royal Electrical and Mechanical Engineers (REME), Royal Veterinary Corps (RVA), Royal Army Medical Corps (RAMC), Royal Logistics Corps (RLC) and so on.
Royal Marines
The RM aren’t technically part of the Army, and have their own unit names. There’s 3 Commando Brigade (Royal Marines), which consists of three commandos (basically, the RM equivalent of infantry battalions) plus support arms. So you might see the name 40 Commando (RM) identifying a Royal Marine unit.
Speaking of the US Armed forces.
I assume the US Army is made up of several Armies.
Also, the US Marines are typically called the “Marine Corp”. Is this a misnomer? Do the US Marines exist as a group of Armies similar to the US Army? Is there no such grouping in the USMC of Army?
Is this naming due to the fact that the Marines existed as a specialized Corp of Army infantry in the past?
Do Marines operate at much smaller levels making the bulk of this heirarchy meaningless?
The largest ‘independent’ fighting unit with integrated support troops is usually the division. A corps is more commonly an ad hoc group of divisions for a particular mission. There are exceptions; I believe the US XVIII Airborne Corps is a ‘permanent’ one since it contains the more mobile, rapid reaction units (82nd Airborne, etc).
An army is a group of corps, but since that means you’re talking about a huge number of units and troops, you’d only see them as administrative units in peacetime (I’m sure someone will correct me if I’m wrong).
The US Marines are more properly titled the US Marine Corps (USMC). It’s not an ‘organisational’ corps like army units, but I think more in common with the British idea of a regiment as a historical and spiritual ‘home’ for the subordinate unit. The USMC also has divisions and the like, and the basic fighting unit is the battalion. USMC units often operate in smaller combined-arms units than the US Army, though – MEUs (Marine Expeditionary Units) and MEBs (Marine Expeditionary Brigades) are, respectively, battalion and brigade-based units with all the supporting air, engineer and artillery assets you’d need for a self-contained operation.
Someone far wiser (and probably a tad more American) than me will have to tell us both about the history, mind.
Yeah, that makes sense. From what I understand, an Armored Cavalry regiment is basically a ‘heavy’ brigade (mostly tanks and Bradleys) except instead of carying squads of mechanised infantry, the Bradleys only carry a few scouts.
Here’s a site that has some US Army field manuals online. It gives some pretty detailed descriptions and org charts of a variety of units.
As far as US Army Corps, there are currently 4 combat corps:
I Corps, Fort Lewis, Washington
III Corps, Fort Hood, Texas
V Corps, Heidelberg, Germany
XVIII Airborne Corps, Fort Bragg, North Carolina
Each, of course, is made up of several divisions, both combat and support.
There are also the the support unit corps such as: Signal Corp, Engineering Corp, Medical Corp, Quartermaster Corp, etc… These are mostly administrative commands that oversee the training, procedures and assignment of the support soldiers.
Crusoe has the gist of Army Groups with
For example:
8th Army Group, Korea
US Army Europe, Germany
US Army Pacific Command, HI
These are basically command and planning commands.
Omniscient, while I’m sure UncleBill can explain the Marines much better than I, one thing I do want to point out. The Marines were a special corp in the US Navy, not the army.
Crusoe: like you say, it’s a bit complex. Here are some examples which illustrate both usages, mostly taken from “official” sites:
“Sometimes Infantry Regiments have more than one unit of this size and they should be correctly referred to as a Battalion and be numbered in ascending order. An example being the 1st Battalion of The Parachute Regiment which like the 2nd Battalion and the 3rd Battalion contains an identical structure and number of posts.”
link
Abbreviated usage: “1st Royal Tank Regiment” link
Full usage: “1st Bn Royal Tank Regiment” link
Abbreviated usage: “1st Parachute Regiment” link
Full usage: “The 1st Battalion The Parachute Regiment” link
(And if this doesn’t make the OP’er give up in disgust, nothing will :D)
[Edited by bibliophage on 09-05-2001 at 01:51 PM]
This is little off-topic, but the table of ranks made me wonder why the U.S. Navy abolished the rank of Commodore and replaced it with “Rear Admiral Lower Half”. Was it to avoid confusion with “Commander”? What sort of command does a one-star Admiral typically have?
Not a bad synopsis.
Considering the Marine Corps End Strength, FY99 was 17,938 officers and 155,383 enlisted (173,321 total personel), they still have a fair number of people to manage. (By comparison, the Navy had 47,809, 282,024, and 384,885)
As for MEU’s:
Absolutely mate. Who needs Gurkhas when you can confuse them into submission!
[Edited by bibliophage on 09-05-2001 at 02:06 PM]