Battalion

A battalion is a military unit, typically consisting of up to one thousand soldiers. A battalion is commanded by a lieutenant colonel and subdivided into several companies, each typically commanded by a major or a captain. The typical battalion is built from three operational companies, one weapons company and one headquarters company. In some countries, battalions are exclusively infantry, while in others battalions are unit-level organizations. The word battalion has its origins in the Late Latin word battalion, which is derived from battalia, meaning "battle" or "combat." The term was used to describe a large group of soldiers ready for battle. Over time, its meaning evolved in military terminology.

The word "battalion" came into the English language in the 16th century from the French bataillon, meaning "battle squadron" (similar to the Italian battaglione meaning the same thing) and the Spanish batallón, derived from the Vulgar Latin noun battalia ("battle") and ultimately from the Classical Latin verb battuere ("to beat" or "to strike"). The first use of the word in English is attested in the 1580s.

A battalion is composed of two or more primary mission companies, which are often of a common type (e.g., infantry, tank, or maintenance), although there are exceptions, such as combined arms battalions in the U.S. Army. In addition to the primary mission companies, a battalion typically includes a headquarters staff and combat service support, which may be combined into a headquarters and service company. A battalion may contain a combat support company. With all these components, a battalion is the smallest military unit capable of "limited independent operations".

The battalion must have a source of resupply to enable it to sustain operations for more than a few days. This is because a battalion's complement of ammunition, expendable weapons (e.g., hand grenades and disposable rocket launchers), water, rations, fuel, lubricants, replacement parts, batteries, and medical supplies normally consists of only what the battalion's soldiers and the battalion's vehicles can carry.^{[citation needed]}

The commander's staff coordinates and plans operations. A battalion's subordinate companies and their platoons are dependent upon the battalion headquarters for command, control, communications and intelligence, and the battalion's service and support structure. The battalion is usually part of a regiment, group, or brigade, depending on the branch of service.^{[citation needed]}

NATO defines a battalion as being "larger than a company, but smaller than a regiment" while "consisting of two or more company-, battery-, or troop-sized units along with a headquarters." The standard NATO symbol for a battalion represented by a pair of vertical lines above a framed unit icon. Member nations have specified the various names they will use for organisations of this size.

In the 16th and 17th centuries, a battalion represented a mass of 3,000–4,000 men, was divided into 15–20 companies, and (since the superstition of the time required odd numbers) was built so as to have 59 ranks in depth and 51 men at the front; while a pikemen, or spearmen, placed in the middle, were surrounded by three ranks of musketeers, other musketeers were located in separate, small quadrangles at the corners of a battalion and were often used as skirmishers (see also Pike and shot). Russia had a gulyay-gorod for a while, an analogue of Pike and shot. The increased effectiveness of artillery fire led to the use of a shallower formation and to the division of these large masses into several battalions. Large cavalry regiments (of 10 squadrons) also began to be divided into 2 battalions.

The term battalion is used in the British Army Infantry and some corps including the Royal Electrical and Mechanical Engineers and Intelligence Corps. It was formerly used in the Royal Engineers (before they switched to regiments), and was also used in the now defunct Royal Army Ordnance Corps and Royal Pioneer Corps. Other corps usually use the term "regiment" instead.