Haldane Reforms in the context of "British Expeditionary Force (World War I)"

The Territorial and Reserve Forces Act 1907 (7 Edw. 7. c. 9) was an act of the Parliament of the United Kingdom that reformed the auxiliary forces of the British Army by transferring existing Volunteer and Yeomanry units into a new Territorial Force (TF); and disbanding the Militia to form a new Special Reserve of the Regular Army. This reorganisation formed a major part of the Haldane Reforms, named after the creator of the act, Richard Haldane.

The lessons learned during the South African War of 1899-1902 had reinforced the idea that the Regular Army was not capable of fighting a prolonged full-scale war without significant assistance; almost all regular units in the United Kingdom had been deployed overseas within four months of the outbreak of hostilities. Furthermore, by the end of the first year of fighting, the Regular Reserve and the Militia Reserve had been entirely exhausted. (Regular reservists were members of the Regular Army who had retired from the active-duty portion of their service but remained available for the callout. The Militia Reserve was a pool of individuals within the Militia, who accepted an overseas service liability). There had been no thought before the war about the wider use of auxiliary forces overseas; in the event, volunteers had been used on an ad-hoc basis, and a new auxiliary arm (the Imperial Yeomanry) was formed to provide specialist troops, but it was clear that a more effective system was required in future. A number of attempts at reform under the Conservative government of 1901-1905 had failed to make any lasting changes to the system and left the auxiliary forces disorganised and demoralised.

The Special Reserve was established on 1 April 1908 with the function of maintaining a reservoir of manpower for the British Army and training replacement drafts in times of war. Its formation was part of the military reforms implemented by Richard Haldane, the Secretary of State for War, which also created the Territorial Force. Haldane originally intended that the Militia would provide the reserve, but opposition from its representatives forced him to abolish it and create the Special Reserve instead. Only 60 per cent of the Militia transferred into the new reserve, and it was consistently under strength, particularly in officers. Reservists enlisted for a six-year term of service, and had to undergo six months of basic training on recruitment and three to four weeks training annually.

The Special Reserve was organised into battalions, providing the third (and sometimes fourth) for each of the regular army's 64 two-battalion infantry regiments and a fifth and sixth for the five four-battalion infantry regiments. In addition to providing replacements to the regular army, the Special Reserve was deployed on home defence duties guarding the coast and key installations during the First World War. The routine nature of its duties meant that scant attention was paid to it in regimental histories. After the war, the Special Reserve was abolished and the Militia was resurrected in 1921 to take on its former role. No effort was made to restart recruitment, and in 1924 the new Militia's functions were absorbed into the Supplementary Reserve.

Richard Burdon Haldane, 1st Viscount Haldane, KT, OM, PC, FRS, FSA, FBA (/ˈhɔːldeɪn/; 30 July 1856 – 19 August 1928) was a Scottish lawyer, philosopher, influential Liberal and later Labour politician and statesman. He was Secretary of State for War between 1905 and 1912 during which time the "Haldane Reforms" of the British Army were implemented. As Secretary of State of War, he was instrumental in founding MI5, MI6, the Territorial Army, the British Expeditionary Force, and the Royal Flying Corps. Beyond his military contributions, Haldane was a significant figure in education, contributing to the founding of institutions such as Imperial College London and the London School of Economics. His efforts have left a lasting impact on both the UK's defence and educational landscapes.

As an intellectual he was fascinated with German thought. That led to his role in seeking detente with Germany in 1912 in the Haldane Mission. The mission was a failure and tensions with Berlin forced London to work more closely with Paris.