battalion

A battalion is a military unit that typically consists of several companies and a headquarters, commanded by a lieutenant colonel. It is a major tactical element in many armed forces and often serves as the principal unit capable of independent operations within a brigade, division, or regiment, depending on national doctrine.

Size and composition vary by country and branch. A typical infantry battalion numbers several hundred to about a thousand soldiers and is organized into three to five line companies plus a headquarters and service company, with a battalion staff including the commander, executive officer, and staff officers. In armored, mechanized, artillery, or engineer branches, battalions are organized around weapons platforms—tank units, artillery batteries, or engineer companies—while retaining a similar command structure.

Role and tasks: battalions conduct offensive and defensive operations, security, and reconnaissance within larger formations. They usually operate under a brigade or regimental command and use their organic maneuver elements in combined-arms operations, supported by attached engineers, medical, and logistics elements.

History: the term battalion derives from French bataille or bataillon, meaning a body of troops. In early modern armies a battalion comprised several companies; by the 18th and 19th centuries it became a standard unit within regiments. Some nations still organize regiments as administrative units, while others use battalions as the primary maneuver element within brigades.

Modern usage: battalions are typically commanded by a lieutenant colonel and form the core of brigades in many forces. In the United States Army, an infantry battalion operates within a brigade and includes multiple rifle companies plus a headquarters company; in the British Army, a similar structure applies.