Division (military)

NATO map symbols

a hostile combined arms division

a friendly infantry division

a hostile tank division

A division is a large military unit or formation, usually consisting of between 10,000 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 during World War II, were used when conditions favored them. In recent times, modern Western militaries have begun adopting the smaller brigade combat team as the default combined arms unit, with the division to which they belong being less important.
A similar word, cat=no/cat=no/cat=no, is also used in Slavic languages 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, in shore commands and in US naval aviation units it refers to an administrative/functional sub-unit of a 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. Among Western military theorists, one of the first to think of organizing an army into smaller combined-arms units was Maurice de Saxe, 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 French and Russian armies to 17,500 in the German imperial army and about 18,000 in Austro-Hungarian and British armies.
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. But, while the number of soldiers was lower, by 1917, divisions were much better armed.
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.

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. 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 to triangular divisions 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 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.
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 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 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

An "infantry division" is a military formation composed primarily of infantry units, also supported by units from other combat arms. In the Soviet Union and Russia, an infantry division is often referred to as a "rifle division". A "motorised infantry" division is a division with a majority of infantry subunits transported on soft-skinned motor vehicles. A "mechanized infantry" division is a division with a majority of infantry subunits transported on armored personnel carriers or infantry fighting vehicles or both, or even some other class of armored fighting vehicles designed for the transportation of infantry. Mechanized infantry divisions in Nazi Germany were called "Panzergrenadier divisions". In Russia, they were known as "motor rifle divisions".
Because of the ease and simplicity involved in forming divisions of infantry compared to other formations, infantry divisions have often been the most numerous in historical warfare. Most US divisions during World War II were infantry divisions.
Infantry divisions were also expected to travel by foot from place to place, with transport vehicles or pack horses used to augment their travel. Divisions evolved over the course of time. For instance, in 1944, Nazi Germany designated some of their infantry formations as Volksgrenadier divisions, which were slightly smaller than the regular divisions, with wider issue of sub-machine guns, automatic and anti-tank weapons to reflect the reality that they were to be used in defensive warfare. In 1945, Nazi Germany seconded members of the Kriegsmarine to create "naval divisions", which were of lower quality than the infantry divisions of the Heer. They also created "Luftwaffe field divisions" from members of the Luftwaffe.
Infantry divisions were sometimes given the responsibility of garrison work. These were named "frontier guard divisions", "static infantry divisions" and "fortress divisions", and were used often by Nazi Germany. The Soviet Union organised Machine-Gun Artillery Divisions of artillery, multiple rocket launchers, and static gun positions for use East of the Urals. A 1997 report said they were generally composed of four brigades, though later data suggests this was inaccurate.