Pre-19th Century Organizations
Early 20th Century Organizations
Late 20th Century Organization
21st Century Organization
Fire and Maneuver
Command Relationships

Pre-19th Century Organizations

How nations organize their armies and how those armies fight are defined by technology, innovative thinking and lessons learned from experience. This essay intends to illuminate the evolution of military organizations throughout history.

From the time of the Roman Legions through the late 18th Century armies were organized into Corps-sized formations. The three primary corps are the Infantry, the Cavalry and the Artillery corps. In ancient days, the "Artillery" corps may have been more accurately referred to as the "Siege" Corps, as crude siege weapons were employed for high impact ranged weapons.

The Infantry and Cavalry corps may have been organized into subordinate echelons. The Roman legion, a subordinate command of the Roman Infantry Corps was further organized into six cohorts. A cohort is similar in size to what we would call a battalion or regiment today. The cohort was divided into ten centuries; which is where the term Centurion is derived. A Roman Century was composed of 70-100 soldiers depending on which author you read and which period of Roman history you read. Various authors have defined the organizational structure differently.

Genghis Khan organized his army into 10-man squads; 10 squads into 10 companies; and 10 companies into 10 "regiments". Genghis Khan also conducted After Actions Reviews (AAR) of all military actions. This was a lessons learned review for the leader and his subordinate commanders. All advanced armies in the world today conduct an AAR at every level from squad to echelons above reality.

17th - 18th Century British Infantry Regiments began life with ~1000 men. The regiment was organized into 10 Companies; similar to Genghis Khan and the Roman Legions. The Regiment had 8 Companies of the Line or Line Companies. These were the units that met the enemy hand to hand and attempted to kill them. The other companies were a Grenadier Company and a Light Company.

The Grenadier Company was composed of large men who were 70" or taller. They were armed with a crude grenade which was lobbed en masse at the enemy. The Grenadier Company was considered an elite unit due to the members' size, they often intimidated their opponents. Later, when the "grenade" went out of style, the units retained their Grenadier status. In some cases, the Grenadier companies were joined together from various regiments and called Grenadier Battalions or Grenadier Regiments.

The Light Company was composed of small men who were 70" or shorter. These men were agile on their feet and could run fast and far. Due to their agility and size, the Light company was often used for picket duty; a means of informing the unit that the enemy was about to attack. Light Companies could be used for long range reconnaissance missions as well. Similar to the Grenadiers, the Light Companies were pooled from various regiments to form Light Battalions or Light Regiments. Eventually Line Regiments removed the Light and Grenadier companies completely and used an 8 Company formation of 800 soldiers.

As regiments incurred losses in the 19th Century and earlier, Armies did not replace them. Therefore, if a unit initially mustered in with 800 soldiers it would be quite possible for them to muster out with two or three hundred or fewer. Most of the losses would have obviously come from death, but a percentage would also be due to loss of limbs or serious illnesses, prisoners of war, and desertions.

Napoleon Bonaparte was the first military thinker to introduce a new formation, what I will call a Combined Arms Corps. Napoleon's Corps is essentially an Independent Command that integrates Infantry, Cavalry and Artillery units under one subordinate command. Napoleon used this new formation at the outset of his campaigns in 1797. Eventually his opponents learned how he operated and utilized these lessons learned for their own uses.

Here is an example of a French Corps at Waterloo:

I Corps - Field Marshal Jean Baptiste d'Erlon (19,800 soldiers & 46 artillery pieces)
1st Division - Baron Quiot (4200 soldiers in 8 Bns & 8 artillery pieces)
1st Brigade - Quiot (2110 soldiers in 4 Bns)
1st & 2nd Bn, 54th Line Infantry (960)
1st & 2nd Bn, 55th Line Infantry (1150)
2nd Brigade - Bourgeois (1880 soldiers in 4 Bns)
1st & 2nd Bn, 28th Line Infantry (900)
1st & 2nd Bn, 105th Line Infantry (980)
Artillery Brigade - Hamelin
20th Battery, 6th Foot Artillery (Hamelin) 85 soldiers, 6x6 pdrs & 2x6" howitzers
5th Company, 1st Train Squadron (Paleprat) 99 soldiers

2nd Division - Francois Donzelot (5300 soldiers in 9 Bns & 8 artillery pieces)
1st Brigade - Schmitz (2915 soldiers in 5 Bns.)
1st, 2nd & 3rd Bns, 3th Light Infantry (1875)
1st & 2nd Bns, 17th Line Infantry (1050)
2nd Brigade - Aulard (2200 in 4 Bns)
1st & 2nd Bns, 19th Line Infantry (1030)
1st & 2nd Bns, 51st Line Infantry (1170)
Artillery Brigade - Cantin (185 soldiers & 8 artillery pieces)
10th Battery, 6th foot Artillery (Cantin) 90 soldiers, 6x6 pdrs & 2x6" howitzers
9th Company, 1st Train Squadron (Vaillant) 95 soldiers

3rd Division - Marcognet (4100 soldiers in 8 Bns & 8 artillery pieces)
1st Brigade - Nogues (1930 soldiers in 4 Bns)
1st & 2nd Bns, 21st Line Infantry (1040)
1st & 2nd Bns, 46th Line Infantry (890)
2nd Brigade - Grenier (1975 in 4 Bns)
1st & 2nd Bns, 25th Line Infantry (975)
1st & 2nd Bns, 45th Line Infantry (1,000)
Artillery Brigade - Emon (180 soldiers & 8 Artillery pieces)
19th battery, 6th Foot Artillery (Emon) 85 soldiers, 6x6 pdrs & 2x6" Howitzers
2nd Company, 1st Train Squadron (Cosqueterre) 95 soldiers

4th Division - Durutte (4,000 in 8 Bns & 8 Artillery pieces)
1st Brigade - Pegot (2135 soldiers in 4 Bns)
1st & 2nd Bns, 8th Line Infantry (985)
1st & 2nd Bns, 29th Line Infantry (1150)
2nd Brigade - Brue (1730 soldiers in 4 Bns)
1st & 2nd Bns, 85th Line Infantry (630)
1st & 2nd Bns, 95th Line Infantry (1100)
Artillery Brigade - Bourgeois (180 & 8 artillery pieces)
9th Battery, 6th Foot Artillery (Bourgeois) 90 soldiers, 6x6 pdrs & 2x6" howitzers
3rd Company, 1st Train Squadron (Drulin) 90 soldiers

1st Cavalry Division - Jacquinot (1700 in 11 Squadrons & 6 artillery pieces)
1st Brigade - Bruno (910 in 6 Sqdns)
7th Hussars (495) *There are 3 Squadrons in a Regiment
3rd Chasseurs (415)
2nd Brigade - Gobrecht (800 in 6 Sqdns)
3rd Lancers (460)
4th Lancers (340)
Artillery Brigade - Bourgeois (160 soldiers & 6 artillery pieces)
2nd Battery, 1st Horse Artillery (Charlet) 75 soldiers, 4x6 pdrs & 2x6" Howitzers
4th Company, 1st Train Squadron (Daux) 85 soldiers

Artillery Reserve - Dessalles (200 soldiers & 8 Artillery pieces) Corps Asset
11th Battery, 6th Foot Artillery (Charlet) 90 soldiers, 6x 12 pdrs & 2x6" howitzers
6th Company, 1st Train Squadron (Didier) 110 soldiers

Engineers - Garbe (355 soldiers) Corps Asset
2nd Company, 1st Engineers (350)

The above organization utilizing Combined Arms Corps or Independent Corps Commands was used all throughout the 19th Century; including The Spanish American War. There are minor changes that occur throughout the century.

Early 20th Century Organizations

World War I witnesses a change in the organization as the Machine gun enters its infancy. Infantry Regiments receive Machinegun Battalions and companies. Entire companies devoted to nothing but Machine guns. By the end of WWI, each Battalion has a Machine gun Company. A standard Infantry Regiment would look like this:

Infantry Regiment
Regimental Headquarters Company
1st Battalion Headquarters Company
A Company (Line)
B Company (Line)
C Company (Line)
D Company (Machine gun)
2nd Battalion Headquarters Company
E Company (Line)
F Company (Line)
G Company (Line)
H Company (MG)
3rd Battalion Headquarters Company
I Company (Line)
K Company (Line)
L Company (Line)
M Company (MG)

With the introduction of the Machine gun company to the Infantry Battalion, the High Impact Ranged weapon we used to see as a distinct corps 200 years prior is now at the Battalion Level.

WWI also saw the introduction of the Tank and the Airplane. To counter both of these the Anti-Tank weapon (AT) and the Anti-Aircraft weapon (AA) were created. The years between the two world wars introduced the Anti-Aircraft Battalions which were included at the Division level and Anti-Tank platoons which were included at the Battalion Level. Scouts and Recon units were also added to the Infantry Battalion. Previously the job of scouting the enemy was performed by Infantrymen. They still are today, but there are also units specifically designed for this purpose.

By 1940, a US Infantry Battalion now consisted of the following:

Battalion Headquarters Company
3x Line Company (A-C for 1st Bn, E-G for 2nd Bn & I-L for 3rd Bn.)
1x Weapons Company

The weapons Company had the Intelligence & Reconnaissance Platoon (I&R) which conducted reconnaissance in front of the Battalion. They may also perform surveillance missions. The Mortar Platoon; generally used the 81mm mortar at Battalion level and 4.2" at Regimental level. The AT platoon was equipped with 57mm AT guns initially and were eventually replaced with the improved 75mm AT gun as enemy Armor improved.

The combined Arms integration of Machine guns, Anti-Tank guns, Mortars and Infantry is now down to the Battalion level. In fact, a standard Line Company now has a weapons Platoon consisting of a section of 60mm Mortars and six .30 caliber MGs. Eventually, company would replace their 60mm Mortars with 81mm and Battalion would replace their 81mm mortars with 4.2" mortars.

The Rifle Squad in World War II consisted of 10 men just as it did in Genghis Khan's Army centuries earlier. Everyone carried the M1 Garand Rifle except the BAR gunner; he carried the Browning Automatic Rifle (BAR). The BAR was no machinegun as it had a limited magazine capacity, but it was full automatic and used a high velocity round. This the beginning of placing the High Impact Ranged weapon at Squad level. The Assistant Squad Leader in a Rifle Squad in WWII also had a grenade projector. He carried the M1903A3 Bolt Action rifle and using a blank cartridge with the grenade projector in order to send a hand grenade flying about 200 yards.

During WWII, German units formed Kampfgruppen or Battle Groups. These battle groups were a Combined Arms unit at the Brigade level (sub-Divisional). Generally they were composed of two battalions of Panzergrenadieren (Mechanized Infantry), a battalion of Panzers (Armor) a Company of Pioneers (Combat Engineers) and a Battalion of Field Artillery. Just as the British, Prussians and Austrians learned from Napoleon 140 years earlier, the Americans, British and Russians learned from the Germans. During the rest of WWII and the Korean War they established combined Arms Teams and Task Forces, but didn't make it permanent until the late 1950's.

Late 20th Century Organization

In 1959, the US Army discarded their regimental system of organizing their army resulting from lessons learned during WWII, Korean War and training experiences of the 1950's. The Combined Arms system went deeper into the organization in this year. Instead of having pure branched regiments of Infantry, Armor and Field Artillery, they were broken up into Battalions. Every Battalion would consist of the following:

Battalion Headquarters Company (battery for FA and troop for cavalry)
4x Line Companies
1x Weapons Company

To further implement the Combined Arms integration, Divisions used Brigades for Subordinate Command instead of Regiments. An Armor Division consisted of five Armor Battalions, five Mechanized Infantry Battalions, three direct support Field Artillery battalions, a general support artillery battalion, a Division Artillery Brigade (DIVARTY), Division Support Command (DISCOM) and eventually the Division Aviation Brigade. A Mechanized Infantry Division consisted of four Armor Battalions, six Mech Infantry Battalions, DIVARTY, DISCOM and AVN BDE. This organization existed until 2005. I retired before the final change occurred.

During the Vietnam War, the rifle squad was composed of 11 soldiers; the squad leader and two fire teams. The fire team was composed of a team leader, Automatic Rifleman (He fired his rifle on full auto), Grenadier (M79 Grenade Launcher) and two Rifleman. The Machine guns in the Company Weapons Platoons were then parceled out to Infantry Platoon level. A Rifle Platoon during Vietnam consisted of three 11-man squads, the Platoon headquarters (3 men) and 2 Machine gun teams of 6 men. This gave the Vietnam Rifle Platoon a strength of 42 soldiers.

The 1970's witnessed the invention of the M203 Grenade Launcher which is attached to the bottom of the rifle. This simple invention reduced the size of a rifle squad from 11 men to 9 men. The M203 removed the Grenadier (M79) and one Rifleman. The introduction of the M47 Dragon Wire Guided Anti-Tank (AT) Missile replaced the older AT guns. By this time the Army had been using 90mm Recoilless Rifles for AT purpose. The M47 was introduced to the Platoon and the Recoilless Rifles went away.

A 1980's Rifle Platoon consisted of

Platoon HQs (Platoon Leader, Platoon Sergeant & Radio/Telephone Operator - RTO)
three 9-man Rifle Squads
one Weapons Squad
The Weapons Squad consisted of the Squad leader, 2 machine gun teams (6 soldiers) and 2 Dragon gunners (M47).
The 1980s Rifle Platoon boasted a strength of 39 soldiers.

Light Infantry units changed again in the 1990's removing all the M47 Dragons to an AT Section at Company level and reduced the MG teams to 2 men instead of 3. The 81mm Mortar Platoon left company level and a Light Weight Company Mortar (LWCM) section consisting of 6 men and 2x 60mm mortars took their place. The 4.2" Battalion mortar was replaced with the 81mm Mortar.

To understand the current organization, one must compare it to the previous one. Prior to the 2005 change, there were three maneuver Brigades, Divarty, Discom and the Aviation Brigade. Since a Mech Infantry Division had four Armor and six mech Infantry battalions, those were organized however the Division Commander wanted to organize them.

A Peace time organization could have looked like this:

4th Infantry Division (Mechanized)
1st Brigade
1st Bn, 8th IN (M)
2nd Bn, 8th IN (M)
1st Bn, 69th AR
2nd Bn, 69th AR
2nd Brigade
3rd Bn, 8th IN (M)
1st Bn, 12th IN (M)
3rd Bn, 69th AR
3rd Brigade
3rd Bn, 12th IN (M)
1st Bn, 22nd IN (M)
1st Bn, 70th AR
DISCOM
4th Engineer Battalion
4th Medical Battalion
1st Battalion 161st Air Defense Artillery (ADA)
124th Signal Battalion
1st Battalion 20th Transportation
704th Maintenance Battalion
412th Maintenance Battalion
4th AG Company
4th Finance Company
4th MP Company
704th MI Battalion
4th ID Band
DIVARTY
2nd Bn, 9th FA (DS) M109 155mm SP
6th Bn, 29th FA (DS) M109 155mm SP
4th Bn, 77th FA (DS) M109 155mm SP
5th Bn, 16th FA (GS) 8" SP
AVN BDE
1st Squadron 10th Cavalry (Armored)
4th Aviation Battalion

When a Maneuver Brigade goes to the field or wartime, slice elements from DISCOM and DIVARTY are generally attached to the Brigade. So in this case, the 1st Brigade goes to the field with its 4 maneuver Battalions plus a Fire Support Team from the 2nd Bn, 9th Field Artillery; it's Direct Support Artillery Battalion. The FA Bn Commander becomes the Fire Support Coordinator for the Brigade. One of the companies from the 704th Maint Battalion will go to the field with the Administrative and Logistics Operations Center (ALOC) of the 1st Brigade. A slice element from 4th Engineers, 4th Medical Battalion, 1st Battalion 161st Air Defense Artillery (ADA), 124th Signal Battalion, 1st Battalion 20th Transportation and the 704th MI Battalion all go with the 1st Brigade to the field. The DISCOM which is a brigade level echelon is purely a peacetime administrative organization. During Field Training Exercises and wartime, they dissolve.

21st Century Organization

In 2005, The Army reorganized again and put all those slice elements right with the Brigades they support in the field. So, the 704th Maintenance Battalion with its 3 Maintenance Companies went away. In its place is the 704th Forward Support Battalion (FSB) consisting of A Company (Transportation Company), B Company (Maintenance Company) and C Company (Medical Company). The FSB would then be permanently assigned to the Brigade it supports. The same thing was done to all the Combat support and Combat Service Support assets. Even the Field Artillery Battalions were absorbed into the maneuver Brigades. The big change is there are now fewer maneuver Battalions per Brigade and there are four Brigades. At first glance it may look like a Division has gotten larger because they have four maneuver Brigades, but in reality they have gotten smaller.



In the diagram above you can see that the DISCOM and DIVARTY have completely dissolved into the maneuver brigades; they no longer exist. The Combined Arms Corps that Napoleon Bonaparte started 200 years ago has been more and more refined.

Fire and Maneuver

The preceding portion of this essay covers how organizations evolved based on advances in technology. Coupled together, they had a significant impact on tactics as well.

The Basic Tactic is called "Fire and Maneuver". The Korean Symbol of Balance; the Ying and the Yang are the Fire (Ying) and Maneuver (Yang) or the hammer and the anvil. In the early 19th Century, European Armies, bombarded the opposing Forces (OPFOR) with massive concentrated Artillery fire. Behind the Artillery came the charging Cavalry. Both the Artillery and the Cavalry sought to create gaps in the enemy lines. The Infantry needed to follow the Cavalry close behind in order to exploit those gaps. If they could put forces on the enemy flanks increasing the volume of fire placed on the enemy, it would cause them to either run away or die in place (DIP).

As technology and organizations change so does the application of this simple technique of "Fire and Maneuver". Originally, it was entire Divisions or Corps doing the maneuver. By the mid 19th Century, it was Battalions and Regiments doing the Fire and Maneuver in massed formations. One battalion stands and fires at the enemy while another Battalion advances. The first Battalion creates a Base of Fire Element (Fire) while the sister Battalion attempts to find advantageous ground. When it does, then the two swap roles and the 2nd Battalion lays down a base of fire while the original battalion moves forward.

Once machine guns were introduced and integrated at the Company and Platoon level, then the Fire and Maneuver technique was applied to squads, platoons and companies. During WWII, a machine gun section reinforced by a rifle squad could lay down a base of fire while the remaining two squads of a platoon maneuver around to the side of an enemy; thereby gaining the advantage.

When Fire teams were created in the 1960's, the application of fire and maneuver then fell upon the squad itself. A team lays down a base of fire while B Team moves to the advantageous ground.

In 1805 it was a French Field Marschal making key battle field decisions and on the modern battlefield, it is the Staff Sergeant and Lieutenant making the key battlefield decisions. This is the evolution of organization and tactics as defined by the changes in technology.

Command Relationships

A Commander is defined as someone appointed as a leader in charge of two to five subordinate units who has the sole responsibility for every person in his command and everything that his command either does or fails to do.

Subordinate Command is a lower echelon command that works with the Commander in order to accomplish his goals following the commander’s single unified vision. The Subordinate commander only answers to his immediate Supervisor/Commander.

Theatre is the region of the world where military operations are taking place. Depending on the size of the operation typically a General (O-10) will be theatre Commander. If more than five armies exist in theatre, Congress may deem necessary to promote a General to General of the Army (O-11), the highest ranking soldier in the Army. If a Theatre commander receives the promotion to General of the Army, then so does the Army Chief of Staff and the Chairman of the Joint Chiefs of Staff (echelons above reality).

One person can only be in command of two to five subordinate units. If only one subordinate unit exists, then no higher commander is required, the subordinate commander is in command. If six subordinate units are available then two commanders will be needed, creating two newly formed subordinate commands to an even higher single unified command. Experience has shown that one person can safely and efficiently control and monitor the activities of no greater than five subordinate units. Therefore the numbers 2-5 are used in determining Command Relationships.

This model can also be applied to the civilian world in managerial relationships. If a company has several departments within their organization, two to five departments which work along similar lines can be grouped under one overseeing manager and so forth. A Regional manager may be placed in charge of two to five Retail outlets. If he is given responsibility for a sixth outlet, the work becomes overwhelming and his attention is distracted thereby providing substandard performance.

Let’s get back to the military Command relationships.

The US Army model of echelons (levels) exists as such:

Fire Team = 4 men with a Sergeant (E-5) leading. It could be 2-5 men.

Squad = 9 men with a Staff Sergeant (E-6) leading and two Fire Teams. The squad leader could control as many as five fire teams if needed, but maintaining two keeps it simple.

Platoon = 34 men with a Lieutenant (O-1/O-2) leading, PLT HQs section, 2 Machine gun teams and three Rifle Squads. The Platoon leader could control 2-5 squads but is typically organized with three for administrative purposes.

Company = 129 men with a Captain (O-3) commanding, Co HQs section, Anti-Armor section, mortar section and three Rifle Platoons. Again the Company Commander could control 2-5 Platoons. During Combined Arms Operations he could possibly receive a platoon of combat engineers and a platoon of armor to conduct a specific operation. A mechanized Infantry Company has a different number of soldiers available.

Battalion = 500 men with a Lieutenant Colonel (O-5) commanding, Headquarters and Headquarters Company and two to five maneuver Companies. The Battalion Commander may find himself with an additional Infantry company from another battalion and an armor Company to support a current operation thereby giving him control of five companies. A mechanized Infantry Battalion has a different number of soldiers available.

Brigade is a subordinate command that technically only has a Brigade Headquarters and Headquarters Company of 70-100 men. There is a Colonel who commands a Brigade. The Brigade Commander is given 2-5 maneuver battalions to command by his Division Commander. An Independent Brigade, not assigned to a division is commanded by a Brigadier General and is equipped with five maneuver battalions.

Division = 10,000 – 15,000 men depending upon the type of organization the division represents. The Division typically has three maneuver brigades (subordinate Commands) which control the 9-10 maneuver battalions assigned to it by the Department of the Army. A Division Commander is a Major General (O-8)

Corps = 2-5 Divisions as assigned by the Theatre Commander. A Corps will also contain a Corps Artillery asset which is of Brigade strength. A Corps can number as few as 20,000 soldiers and as many as 75,000. A Corps Commander is typically a Lieutenant General (O-9). This is definitely “echelons above reality”.

Army = 2-5 Corps will be assigned to an Army by the Department of the Army or Army Chief of Staff. An Army will have additional assets including an Artillery asset and many other Combat Service Support Assets. A General will command an Army (O-10). You will find anywhere from 40,000 to 375,000 troops in an Army.

Army Group = 2-5 Armies or 80,000 to nearly 2 million soldiers. Typically the Army Group is not used unless there is a major campaign going on. If a theatre command has greater than five armies available to them, the Army Group will be used as an intermediate command between Army and Theatre. The Army Group Commander is also a General (O-10) but due to command relationship he outranks his subordinate commanders at Army level.