The British Militia was the principal military reserve force of the United Kingdom of Great Britain and Ireland.

Militia units were repeatedly raised in Great Britain during the Victorian and Edwardian eras for internal security duties and to defend against external invasions.

Some consideration was given to recruiting foreign nationals; however, on 4 November 1813 a bill was introduced to Parliament to allow Militia volunteers to serve in Europe.

[2][page needed] After the Napoleonic Wars, the Militia fell into disuse, although regimental colonels and adjutants continued to appear in the Army List.

The full army pay during training and a financial retainer thereafter made a useful addition to the men's civilian wage.

The militia thus appealed to agricultural labourers, colliers and the like, men in casual occupations, who could leave their civilian job and pick it up again.

[12] The possibility of enlisting in the army under Regular terms of service were facilitated under paragraph 38, one precondition was that the recruit 'fulfils the necessary physical requirements.

[12] Upon mobilisation, the special reserve units would be formed at the depot and continue training while guarding vulnerable points in Britain.

In the aftermath of the Munich Crisis Leslie Hore-Belisha, Secretary of State for War, wished to introduce a limited form of conscription, an unheard of concept in peacetime.

Only single men aged 20–22 were to be conscripted (given a free suit of civilian clothes as well as a uniform), and after six months full-time training would be discharged into the reserve.