An army battalion is a mid-size military subdivision generally commanded by an officer around the rank of Colonel. Depending on the particular army, a battalion can consist of anywhere from several hundred to more than a thousand troops, themselves organized in numerous smaller units. In turn, multiple battalions make up larger units, such as regiments and divisions. Battalions are considered to be the smallest units in an army capable of operating autonomously, without larger support.
The various characteristic details of a battalion differ between national armies. Variations can exist in total composition, officer ranks and complement as well as the presence and number of support units. In Canada for instance, a typical battalion is a reserve unit with no more than 200 troops. A United States Army battalion, by comparison, numbers as many as 1,200 soldiers organized into as many as five or more companies.
Common in virtually every military, however, is the fact that an army battalion is highly focused in scope. For instance, a tank battalion almost always consists only of tank and support companies. Infantry battalions, by comparison, are commonly limited only to infantry and related units. An army battalion typically will have one company designated as its headquarters, or HQ company, that houses the command section of the battalion and disseminates orders.
The staff of a headquarters company generally includes a variety of senior officers. The complement may include a communications officer, medical officer, logistics officer, public affairs officer, a Judge Advocate General (JAG) officer, and more. HQ companies also include enlisted men and non-commissioned officers as in regular companies.
In the United States army and many others, there are a variety of non-combat battalions whose duties are more focused on the numerous support areas essential to the smooth running of the overall army. These include units dedicated to recruitment, medical care, garrison and base-support, and other specific duties. There are numerous brigades dedicated to these operations, themselves composed of many battalions. Recruiting battalions, in particular, also include a large proportion of civilian staff.
Other common types of combat army battalions include field artillery, air defense, airborne, special forces, and mechanized infantry, among others. Each of these battalions has a different objective and composition. Due to this specialization, training methods may vary widely and lead to individual battalions having a unique character and overall disposition of its units.
There are many army battalions that have won fame and glory throughout history. Perhaps one of the most notable is the so-called "Lost Battalion of World War One." Nine companies from the United States 77th Infantry Division were left behind German lines in the Argonne Forest of Germany in October 1918, following a larger offensive, and suffered catastrophic losses before being rescued.
Of the roughly 575 troops who were left exposed, fewer than 200 survived to be rescued. Relief did not come until after nearly a week of isolation and heavy German attacks. The heroism of the Lost Battalion and its commander, Major Charles Whittlesey, has been the subject of numerous nonfiction books and an eponymously-titled movie produced in the United States in 2001.