The British Army's Infantry takes on a variety of roles, including armoured, mechanised, air assault and light.

Traditionally, regiments that form the combat arms of the British Army (cavalry and infantry) recruit from specific areas of the country.

Infantry regiments had been assigned specific areas from which they would recruit from by the mid eighteenth century.

This course, called the "Combat Infantryman's Course" (CIC), lasts 26 weeks as standard and teaches recruits both the basics of soldiering (Phase 1 training) and the specifics of soldiering in the infantry (Phase 2 training).

The other major independent element of the Reaction Force is UK Commando Force; although this does have British Army units attached in combat support roles, the infantry units are from the Royal Marines, which is part of the Naval Service.

[note 1] 3rd (UK) Division is planned as the UK's main reaction force, intended to act as a lead formation alongside NATO, and primarily consists of a pair of armoured brigades containing the army's mechanised infantry units.

The formation has responsibility for two separate infantry brigades, both of which are optimised to a training role - one is primarily intended as a mentoring formation for the UK's allies, while the other is the Army Special Operations Brigade, which contains those infantry units dedicated to military training and operational support for the UK's partner nations.

Infantry units are attached to a number of other formations that are independent of the British Army's three existing divisions.

Following the end of the Second World War, reductions in the size of the infantry led to the amalgamation of the existing regimental depots, together with their operational battalions, into geographically based infantry depots, each designated by a letter of the alphabet from A to O (not including I).

This was taken a stage further following the 1957 Defence White Paper, when each brigade adopted a single cap badge that would be worn by all of the regiments under its administration.

This led to discussions within the government regarding the flexibility of the infantry under the then present regimental system, as well as the difficulty of potentially making reductions to the size of the army owing to the emotive nature of the amalgamation of regiments into single battalions.

[11] This process had to a certain degree begun in the East Anglian and Green Jackets Brigades, which had redesignated the regiments they were responsible for from their old names to numbered designations.

The amalgamations into large regiments coincided with a planned reduction in the size of the infantry – the intention was that the junior battalion of each large regiment or brigade (prior to the implementation of the divisional structure) would be removed, whether by amalgamation or disbanding.

HM Treasury asked for major cuts in the strength of the infantry in 2003, with at least ten battalions to be disbanded.

This proved so unacceptable that, in November 2003, there was consideration to instead reducing each battalion to two rifle companies (with the third to come from the TA).

To ensure that officers and men could continue to gain the variety of skills that the arms plot provided, the restructuring would also see a series of amalgamations of the remaining single battalion infantry regiments into large regiments.

The roles are divided up as follows: The reorganisation was a hybrid of the systems used to organise the regular infantry in Australia and Canada.

The air assault battalion will be reduced to company strength, with the intention that it is assigned as a permanent public duties unit in Scotland.

Under a further review called Army 2020 Refine, the 1st Battalion, Scots Guards and the 4th Battalion, The Royal Regiment of Scotland will be equipped with Mechanised Infantry Vehicles and form the core of the first Strike Brigade under the Reaction Force.

[27] Since the Cardwell reforms began, infantry regiments in the British Army have amalgamated on many occasions.