began during World War I when the British
government passed the Military Service Act
in 1916. The act specified that single men 18 to 41 years old were liable to be called up for military service unless they were widowed with children or ministers of a religion. There was a system of tribunals to adjudicate upon claims for exemption upon the grounds of performing civilian work of national importance, domestic hardship, health, and conscientious objection
. The law went through several changes before the war ended. Married men ceased to be exempt in June 1916, and the age limit was eventually raised to 51 years old
. Recognition of work of national importance also diminished, and in the last year of the war there was some support for the conscription of clergy.[citation needed
] Conscription lasted until mid-1919.
At the start of 1914 the British Army
had a reported strength of 710,000 men including reserves, of which around 80,000 were regular troops ready for war
. By the end of World War I
almost 1 in 4
of the total male population of the United Kingdom of Great Britain and Ireland
had joined, over five million men.