When the Territorial Force (TF) was created in 1908 it was a part-time volunteer force intended for home defence when the Regular British Expeditionary Force (BEF) was deployed overseas, although a small number of TF units had volunteered for 'Imperial Service'. With the outbreak of World War I the TF was mobilised on 4 August 1914 and went to its war stations. However, on 10 August the TF was invited to volunteer for overseas service, and the majority of men and units did so. Those who did not volunteer or were unfit for overseas service were separated on 15 August to form the basis for reserve units to train the mass of volunteer recruits coming forward. From 31 August these reserve units were termed '2nd Line', distinguished from their 1st Line parents by a '2/' prefix. In this way duplicate units and formations came into being.[1][2]
Provisional units
By May 1915 it was decided to prepare the 2nd Line TF units for overseas service, and 3rd Line training units were created to supply reinforcements to the 1st and 2nd Lines. At the same time the remaining home service and unfit personnel were separated and grouped into coast defence brigades, shortly afterwards termed provisional brigades. The provisional infantry battalions were numbered up to 108 (with some gaps in the sequence). Support units (Royal Field Artillery, Royal Engineers, Army Service Corpsetc), took the number of the provisional brigade to which they belonged.[3][4][5][6]
The Military Service Act 1916 swept away the home/foreign service distinction, and all TF soldiers became liable for overseas service, if medically fit. The provisional brigades thus became anomalous, and on 1 January 1917 the remaining infantry units became numbered battalions of appropriate regiments.[4][5][7]
Maj A.F. Becke,History of the Great War: Order of Battle of Divisions, Part 2a: The Territorial Force Mounted Divisions and the 1st-Line Territorial Force Divisions (42–56), London: HM Stationery Office, 1935/Uckfield: Naval & Military Press, 2007, ISBN1-847347-39-8.
Maj A.F. Becke,History of the Great War: Order of Battle of Divisions, Part 2b: The 2nd-Line Territorial Force Divisions (57th–69th), with the Home-Service Divisions (71st–73rd) and 74th and 75th Divisions, London: HM Stationery Office, 1937/Uckfield: Naval & Military Press, 2007, ISBN1-847347-39-8.
J.B.M. Frederick, Lineage Book of British Land Forces 1660–1978, Vol I, Wakefield: Microform Academic, 1984, ISBN1-85117-007-3.
Capt F. Clive Grimwade, The War History of the 4th Battalion The London Regiment (Royal Fusiliers) 1914–1919, London: Regimental Headquarters, 1922/Uckfield, Naval & Military Press, 2002, ISBN978-1-843423-63-8.
Brig E.A. James, British Regiments 1914–18, London: Samson Books, 1978, ISBN0-906304-03-2/Uckfield: Naval & Military Press, 2001, ISBN978-1-84342-197-9.
Maj H.O. Lock, History of the Dorsetshire Regiment, 1914–1919, Part II: The Territorial Units, Dorchester: Henry Ling, 1933/Uckfield: Naval & Military, 2002, ISBN978-1-84342209-9.
Lt-Col C.C.R. Murphy, The History of the Suffolk Regiment 1914–1927, London: Hutchinson, 1928/Uckfield: Naval & Military, 2002, ISBN978-1-84342-245-7.
Regimental History Committee, The Northamptonshire Regiment, 1914–1918, Aldershot: Gale & Polden, 1932/Uckfield: Naval & Military, 2005, ISBN1-845742-70-2.
Maj-Gen C.R. Simpson (ed), The History of the Lincolnshire Regiment 1914–1918, London: Medici Society, 1931//Uckfield: Naval & Military Press, 2002, ISBN978-1-84342-355-3.
War Office, Army Council Instructions Issued During January 1916, London: HM Stationery Office, 1916.
Col H.C. Wylly, History of the Queen's Royal (West Surrey) Regiment in the Great War, Aldershot: Gale & Polden, 1925/Uckfield, Naval & Military Press, 2003, ISBN978-1-84342539-7.