Conscription in the United Kingdom has existed for two periods in modern times. The first was from 1916 to 1920, the second was from 1939 to 1960, with the last conscripted soldiers having left the service in 1963. Known as Military Service from 1916 to 1920, the system of conscription from 1939 to 1960 was called National Service, but, between 1939 and 1948, it was often referred to as "war service" in documents relating to National Insurance and pension provision.
Conscription during the First World War began when the British government passed the Military Service Act in 1916. The act specified that single men aged 18 to 40 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 Military Service 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 were exempt in the original Act, although this was changed in June 1916. The age limit was also 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. Conscription lasted until mid-1919.
Due to the political situation in Ireland, conscription was never applied there; only in England, Scotland and Wales.
Conscription legislation lapsed in 1920. However, as a result of the deteriorating international situation and the rise of Nazi Germany, Leslie Hore-Belisha, Secretary of State for War, persuaded the cabinet of Neville Chamberlain to introduce a limited form of conscription on 27 April 1939, with the Military Training Act being passed the following month. Only single men 20 to 22 years old were liable to be called up, and they were to be known as "militiamen" to distinguish them from the regular army. To emphasise this distinction, each man was issued with a suit in addition to a uniform. The intention was for the first intake to undergo six months of basic training before being discharged into an active reserve. They would then be recalled for short training periods and attend an annual camp.