NATO map symbols a friendly combined arms division a hostile combined arms division a friendly infantry division a friendly airborne infantry division a hostile tank division
A division is a large military unit or formation, usually consisting of between 6,000 and 25,000 soldiers. In most armies, a division is composed of several regiments or brigades; in turn, several divisions typically make up a corps.
Historically, the division has been the default combined arms unit capable of independent operations. Smaller combined arms units, such as the American regimental combat team (RCT) during World War II, were used when conditions favored them. In recent times, modern Western militaries have begun adopting the smaller brigade combat team (similar to the RCT) as the default combined arms unit, with the division to which they belong being less important.
A similar word, //, is also used in Slavic languages (such as Russian, Serbo-Croatian, and Polish) for a battalion-size artillery or cavalry unit. In naval usage "division" has a completely different range of meanings. Aboard ships of British Royal Navy tradition, the terms "division" or "department" are often used interchangeably and refer to the administrative organization used to manage personnel. Aboard US Navy ships (including US Coast Guard vessels), in shore commands and in US naval aviation units (including US navy, marine corps, and coastguard aviation) it refers to an administrative/functional sub-unit of a department (e.g., fire control division of the weapons department). Alternatively it refers to a sub-unit of several ships within a flotilla or squadron, or to two or three sections of aircraft operating under a designated division leader.
History Origins
In 1577, the Devon Trained Bands of England were divided into three divisions, each with two colonels and six captains.Col. Henry Walrond, Historical Records of the 1st Devon Militia (4th Battalion The Devonshire Regiment), With a Notice of the 2nd and North Devon Militia Regiments, London: Longmans, 1897/Andesite Press, 2015, Among Western military theorists, one of the first to think of organizing an army into smaller combined-arms units was Maurice de Saxe (d. 1750), Marshal General of France, in his book Mes Rêveries. He died at the age of 54, without having implemented his idea. Victor-François de Broglie put the ideas into practice. He conducted successful practical experiments of the divisional system in the Seven Years' War.
Early divisions The first war in which the divisional system was used systematically was the French Revolutionary War. Lazare Carnot of the Committee of Public Safety, who was in charge of military affairs, came to the same conclusion about it as the previous royal government, and the army was organised into divisions.
It made the armies more flexible and easy to maneuver, and it also made the large French Revolutionary Army manageable. Under Napoleon, the divisions were grouped together into corps, because of their increasing size. Napoleon's military success spread the divisional and corps system all over Europe; by the end of the Napoleonic Wars, all armies in Europe had adopted it.
World War I The composition of divisions varied significantly during the two world wars and, in addition, there was no uniformity of quality, even when divisions had the same composition.
The size of infantry divisions deployed by the major belligerents at start of the Great War ranged from about 16,000 in the FrenchThe French division of 1914 was made of two brigades, each of two regiments with three battalions, plus a reserve regiment of two battalions, an artillery regiment of nine batteries (36 x 75 mm guns), a cavalry squadron and a company of engineers. The reserve division had two infantry brigades, each with three regiments of two battalions, two cavalry squadrons and three artillery groups of three batteries. and Russian armies to 17,500 in the German imperial armyGerman infantry division in 1914 was organized into 2 brigades. Each brigade had 2 regiments; each regiment had 3 battalions (26 officers and 1050 men per battalion); and each battalion had 4 companies. Thus, the division had 12 battalions. Beside its rifle power, the division had 24 machine guns, and the field artillery numbered 72 guns (54 guns of 77mm and 18 guns of 105mm) The German corps, in addition to containing supply, communication, and hospital units, provided heavier artillery for the support of the divisions, with either 32 150mm howitzers or 16 210mm howitzers. and about 18,000 in Austro-HungarianThe Austro-Hungarian infantry division numbered between 12,000 and 18,000 men, while the cavalry divisions averaged 5,000 fewer soldiers. Each division had a brigade of artillery (with 54 guns, but few divisions had that many guns) and two brigades of infantry or cavalry; with two regiments of infantry or cavalry per brigade. Each regiment of infantry had 4 battalions of 1,100 men at full strength, although, in practice, many regiments deployed with just three battalions. Each cavalry regiment had to divisions (a battalion-sized unit) of about 700 each. At the outbreak of war, the Austro-Hungarian army had 48 infantry divisions (including seven Landweher and eight Honved) and eleven cavalry divisions (of which two were Honved). In 1914, the Austro-Hungarian division had less artillery than most other European divisions, save the Italian. The German division had as many as 72 pieces, the Russian sixty. and British armies.A British infantry division in 1914 was composed of 3 brigades. Each brigade had 4 battalions (35 officers and 1000 men per battalion); each battalion had four companies; and each company had 4 platoons. Thus, the division had 12 battalions. In addition to rifle power of its battalions, the division was armed with 24 machine guns, and its field artillery numbered 76 guns (54 guns of 18-pdrs.; 18 howitzers of 4.5-inch; and 4 of 60-pdrs.).
As World War I went on, the size of divisions decreased significantly from those of 1914, with both British and Germans reducing the number of divisions' sub-units.By 1918, many British infantry divisions were down to about 15,000 men. Partially because in 1918 the number of battalions per brigade was reduced from 4 to 3, and in part because reinforcements did not fully replace losses (battalions might number 800 or 900 men, significantly below the authorized 1000). In 1917, the Germans eliminated their brigade structure and reduced the number of regiments per division to 3, each regiment having 3 battalions. Furthermore, the Germans, also reduced the number of companies in a battalion from 4 to 3. As such, the number of riflemen in the division dropped from 11,520 to 6,460; however, it more than gained in other weapons. But, while the number of soldiers was lower, by 1917, divisions were much better armed.For example, a German 1917 division now had 48 mortars, a weapon not in its 1914 inventory, and by the winter of 1917–18, the number of machine guns had increased from the initial 24 to 358 (142 heavy and 216 light)
On the other hand, in 1917, the American infantry divisions that arrived in France numbered 28,061 officers and men, of which 17,666 were riflemen.Beside rifle power, the US division had 260 machine guns, and 72 guns (48 75mm and 24 155mm), along with various units for engineering, communication, and supply An in depth analysis of US divisional organization in during the Great War
World War II The divisional system reached its numerical height during the Second World War. Beside the infantry and cavalry divisions created since Napoleonic era, new division types appeared during the Second World War, such as airborne, tank, mechanized, motorized.
The Soviet Union's Red Army consisted of more than a thousand division-sized units at any one time, and the number of rifle divisions raised during the Great Patriotic War of 1941–1945 is estimated by David M. Glantz as 482.David M. Glantz Colossus Reborn: The Red Army at War, 1941–1943. University Press of Kansas, 2005, p. 576. Nazi Germany had hundreds of numbered or named divisions, while the United States employed up to 91 divisions.
A notable change to divisional structures during the war was completion of the shift from square divisions (composed of two brigades each with two regiments) to triangular divisions (composed of three regiments with no brigade level) that many European armies had started using in World War I. This was done to increase flexibility and to pare down chain-of-command overhead. The triangular division structure allowed the tactic of "two forward, one back", where two of the division's regiments could engage the enemy with one regiment in reserve.
All divisions in World War II were expected to have their own artillery formations, usually (depending upon the nation) the size of a regiment. Divisional artillery was occasionally seconded by corps-level command to increase firepower in larger engagements.
During the war the US also used regimental combat teams, whereby attached and/or organic divisional units were parceled out to infantry regiments, creating smaller combined-arms units with their own armor and artillery and support units. These combat teams would still be under divisional command but had some level of autonomy on the battlefield.
Organic units within divisions were units which operated directly under divisional command and were not normally controlled by the regiments. These units were mainly support units in nature, and included signal companies, medical battalions, supply trains and administration.War Department. (1945, January). Signal operations in the corps and army (Field Manual 11‑22). Retrieved July 30, 2025, from Internet Archive.
Attached units were smaller units that were placed under divisional command temporarily for the purpose of completing a particular mission. These units were usually combat units such as tank battalions, tank-destroyer battalions or cavalry-reconnaissance squadrons.
Modern divisions In modern times, most military forces have standardized their divisional structures. This does not mean that divisions are equal in size or structure from country to country, but divisions have, in most cases, come to be units of 10,000 to 15,000 soldiers with enough organic support to be capable of independent operations. Usually, the direct organization of the division consists of one to four brigades or battle groups of its primary combat arm, along with a brigade or regiment of combat support (usually artillery) and a number of direct-reporting battalions for necessary specialized support tasks, such as intelligence, logistics, reconnaissance, and combat engineers. Most militaries standardize ideal organization strength for each type of division, encapsulated in a Table of Organization and Equipment (TO&E) which specifies exact assignments of units, personnel, and equipment for a division.
The modern division became the primary identifiable combat unit in many militaries during the second half of the 20th century, supplanting the brigade; however, the trend started to reverse since the end of the Cold War. The peak use of the division as the primary combat unit occurred during World War II, when the belligerents deployed over a thousand divisions. With technological advances since then, the combat power of each division has increased.
Types Divisions are often formed to organize units of a particular type together with appropriate support units to allow independent operations. In more recent times, divisions have mainly been organized as combined arms units with subordinate units representing various combat arms. In this case, the division often retains the name of a more specialized division, and may still be tasked with a primary role suited to that specialization.
Infantry division