The basic hierarchy of the army

What is an order of battle?

An Order of Battle (often shortened to ORBAT) is the identification, strength, command structure and disposition of the personnel, units and equipment of any military force. It is an organisational view of the army.

The basic structure

Many people find the various names of organisational units very confusing. There is good reason for this: it is confusing! For example the word Corps was used in three quite distinct ways. The word Brigade was used to describe different units of the infantry, cavalry and artillery … and what about the Rifle Brigade? That is a regiment of infantry! The Brigade of Guards? That is a collection of Guards regiments and is not a Brigade at all!

We can simply this by looking at the army’s hierarchy in this way, starting with the individual soldier. This is simplified but works in most cases.

  • Soldier -> in the infantry, he is part of a Battalion (c. 1000 men) This is subdivided into four Companies, which are each subdivided into four Platoons, which are each subdivided into four Sections.
  • several Battalions -> are under command of a Brigade (c.5000 men)
  • several Brigades -> are under command of a Division (c.20000 men)
  • several Divisions -> are under command of a Corps
  • several Corps -> are under command of an Army
  • several Armies (the British eventually had five in France and Flanders) -> under command of a GHQ, General Headquarters
  • GHQ -> under command of the War Office.

The arrangements and names are a little different in the artillery:

  • Soldier -> in the artillery, he is part of a Battery or Ammunition Column (which is subdivided into Sections)
  • several Batteries and an AC -> are under command of a Brigade
  • several Brigades -> are under command of a Division, etc

How the Long, Long Trail can help

The constituent parts and history of every formation are here. The histories units of the various units appear in the appropriate pages on infantry, artillery and so on. The structure and hierarchy of formations is in the Order of Battle pages.