British home army in the First World War

British home army 1914–1918
Country	United Kingdom
Branch	British Army
Type	Army
Role	Land warfare
Part of	British Armed Forces
Commanders
Commander-in-Chief, Central Force	General Ian Hamilton
Director of Home Defence	Lieutenant-General Launcelot Kiggell[1]
Commander-in-Chief, Home Forces	Field Marshal Viscount French
Commander-in-Chief, Home Forces	General Sir William Robertson

The British home army in the First World War served the dual purpose of defending the country against invasion and training reinforcements for the army overseas. Initial responsibility for defending the nation lay with the Territorial Force, a part-time auxiliary designed in 1908 as a means of expanding the army in a major foreign conflict but, as a result of political compromise, implemented as a home defence army. It was supported in this role by 42,000 regular army troops, primarily belonging to the Royal Garrison Artillery and the Royal Engineers. The 14 infantry divisions and 14 mounted brigades of the Territorial Force were mainly allocated either to the Local Force, stationed near the coast and tasked with disrupting an invasion at the point of landing, or the Central Force, a mobile element tasked with defeating the invading force as it marched on London. The Local Force was augmented by units of the Special Reserve and Extra Reserve, which were the third battalions of the regular army line infantry regiments established to recruit and train replacements for their regiments' two combat battalions. The home army was also largely responsible for guarding vulnerable points, such as the communications infrastructure, rail network and munitions works.

Although the territorials could not be compelled to serve outside the United Kingdom, they could volunteer to do so, and when large numbers did, units of the Territorial Force began to be posted overseas. By July 1915, the home army had been stripped of all its original territorial divisions, and their places in the home defences were taken by second-line territorial units. The new units competed for equipment with the 'New Army' being raised to expand the army overseas, the reserves of which were also allocated to home defence while they trained, and suffered from severe shortages. The second line's task in home defence was also complicated by having to supply replacement drafts to the first line and the need to train for their own eventual deployment overseas. Most of the second line divisions had departed the country by 1917, and the territorial brigades in those that remained were replaced by brigades of the Training Reserve, created in 1916 by a reorganisation of New Army reserve units.

To make up the losses, the duties of the home army were increasingly performed by personnel unsuitable for service at the front. The National Reserve, comprising men above military age with previous military experience, relieved territorials in guarding vulnerable points. It was re-organised in early 1916 as the Royal Defence Corps which, in 1917, also began to man coastal defences. Older members of the National Reserve played a leading role in the development of the Volunteer Training Corps. This was a spontaneous civilian movement which sprang into existence as soon as war was declared and assisted the home army in a variety of duties, including the digging of the London defences and the guarding of vulnerable points. The movement was initially met by the authorities with antipathy and censure, but it was formally recognised in 1916 as an official military auxiliary and incorporated, as the Volunteer Force, into the anti-invasion plans.

A shortage of manpower at the end of 1917 resulted in further significant reductions in the home army. Four of its eight divisions were disbanded, and the partially trained 19-year-olds in the remainder were replaced with raw 18-year-old recruits. The problem was exacerbated by the heavy losses suffered as a result of the German spring offensive in March 1918. The home army was stripped of all available personnel, leaving its ranks populated by under-aged, largely untrained recruits and low-category territorials, supported by part-time amateur auxiliaries recruited from men exempted from conscription, the medically unfit and the over-aged. Despite the military authorities' belief that it was militarily worthless, the Volunteer Force was partially mobilised and deployed to augment the coastal defences. The crisis passed in August, and by the following the month the invasion threat was downgraded to no more than a raid not exceeding 5,000 troops. The home defences were wound down, and the home army was rationalised as a training organisation dedicated to the provision of replacements to the front-line units overseas. After the war, home defence forces were demobilised with scant recognition given for their services. The Territorial Force was reconstituted as the Territorial Army and the Royal Defence Corps reappeared as the National Defence Corps, but the National Reserve and the Volunteer Force were not revived.