Battalion

A Battalion is a military unit of the UNSC Army and Marine Corps, normally consisting of two to six companies, anywhere from five hundred to one thousand men.

Function

 * Tank and mechanized infantry battalion task forces apply their combat power to—
 * Conduct sustained combat operations in all environments with proper augmentation and support.
 * Conduct offensive operations.
 * Conduct defensive operations.
 * Accomplish rapid movement and limited penetrations.
 * Exploit success and pursue a defeated enemy as part of a larger formation.
 * Conduct security operations (advance, flank, or rear guard) for a larger force.
 * Conduct stability operations and support operations as part of a larger force.
 * Conduct operations with light infantry forces.

A battalion unit is generally considered the smallest unit able to conduct independent operations.

Composition
Using the US Army and Marine Corps model as an example, a battalion is normally composed of three rifle/infantry companies, each designated by a letter (A through M, depending on which battalions within a single regiment a company is part of), as well as a Headquarters and Service Company (H&S Company) (Marine Corps) or a Headquarters and Headquarters Company (HHC) (Army) including the commanding officer (usually a Lieutenant Colonel or Colonel) and executive officer (usually a Major), a Sergeant Major and executive staff. These are usually supplemented by a Weapons Company, which does not use a letter-designation.

A Regiment or Brigade is composed of several battalions.

Known Battalions

 * 2nd Shock Troops Battalion
 * 7th Shock Troops Battalion
 * 10th Shock Troops Battalion
 * 11th Shock Troops Battalion
 * 15th Shock Troops Battalion
 * 19th Shock Troops Battalion
 * 22nd Shock Troops Battalion
 * 1st Battalion 12th Marines
 * 3rd Battalion 12th Marines
 * 4th Battalion 12th Marines
 * 5th Battalion 12th Marines
 * 3rd Battalion Reserves
 * 3rd Battalion, 8th Armored Brigade
 * 13th Battalion
 * 79th Infantry Battalion
 * 554th Battalion, 34th Infantry Brigade
 * 717th Xeno-Materials Exploitation Battalion
 * M-EDF 9/21/1
 * E2-BAG/1/7

List of appearances

 * Halo 2
 * Halo 3: ODST
 * Halo: Reach
 * Halo: The Flood
 * Halo: Ghosts of Onyx
 * Halo: Contact Harvest
 * Halo: Landfall
 * Halo: Last One Standing