# List of divisions of the British Territorial Force 1914–1918

The Territorial Force was established on 1 April 1908 as a volunteer auxiliary to the British Army. It was formed by the amalgamation of the former auxiliary institutions of the Volunteer Force and the yeomanry. Designed primarily as a home defence force, its members could not be compelled to serve overseas unless they volunteered to do so. On the outbreak of the First World War in 1914, many did. The first units were deployed piecemeal in support of the regular army as it defended against the opening German offensive in Belgium and France in 1914. The first territorial divisions to be deployed were used to free up imperial garrisons overseas, but in 1915 they began to be deployed to the front lines on the Western Front and at Gallipoli. The pre-war territorial divisions were numbered in May 1915 in order of their deployment. As they were deployed, second-line divisions were raised to replace them at home, and in 1916 these began to be deployed to combat zones. By the end of the war in 1918, the Territorial Force had provided 28 divisions and 14 mounted brigades.

## Infantry divisions

| Number | Name | Second-line | Recruitment Area | Notes |
| 42nd | East Lancashire Division | 66th (2nd East Lancashire) Division | Cumberland, part of Lancashire and Westmorland | |
| 43rd | Wessex Division | 45th (2nd Wessex) Division | Cornwall, Devon, Dorset, Hampshire, Somerset, Wiltshire | |
| 44th | Home Counties Division | 67th (2nd Home Counties) Division | Middlesex, Kent, Surrey and Sussex | Second-line division lost territorial association early 1918 |
| 46th | North Midland Division | 59th (2nd North Midland) Division | Derbyshire, Leicestershire, Lincolnshire, Nottinghamshire, Rutland and Staffordshire | |
| 47th | 2nd London Division | 60th (2/2nd London) Division | County of London | |
| 48th | South Midland Division | 61st (2nd South Midland) Division | Berkshire, Buckinghamshire, Gloucestershire, Oxfordshire and Warwickshire | |
| 49th | West Riding Division | 62nd (2nd West Riding) Division | West Riding of Yorkshire | |
| 50th | Northumbrian Division | 63rd (2nd Northumbrian) Division | County Durham, Northumberland, East and North Ridings of Yorkshire | Second-line division broken up in July 1916 |
| 51st | Highland Division | 64th (2nd Highland) Division | Aberdeen and Dundee, the counties of Aberdeenshire, Argyllshire, Banffshire, Buteshire, Caithness, Clackmannanshire, Dunbartonshire, Elginshire, Fife, Forfarshire, Inverness-shire, Kinross-shire, Nairnshire, Renfrewshire, Shetland, Stirlingshire, Sutherland and part of Lanarkshire | Second-line division lost territorial association early 1918 |
| 52nd | Lowland Division | 65th (2nd Lowland) Division | Edinburgh and Glasgow, Counties of Berwickshire, Dumfriesshire, Haddingtonshire, Kirkcudbrightshire, Linlithgowshire, Midlothian, Peeblesshire, Selkirkshire, Wigtownshire and part of Lanarkshire | Second-line division broken up 18 March 1918 |
| 53rd | Welsh Division | 68th (2nd Welsh) Division | Wales, Monmouthshire, Cheshire, Herefordshire and Shropshire | Second-line division lost territorial association early 1918 |
| 54th | East Anglian Division | 69th (2nd East Anglian) Division | Bedfordshire, Cambridgeshire, Essex, Hertfordshire, Huntingdonshire, Norfolk, Northamptonshire and Suffolk | Second-line division lost territorial association early 1918 |
| 55th | West Lancashire Division | 57th (2nd West Lancashire) Division | Lancashire and Liverpool | |
| 56th | 1st London Division | 58th (2/1st London) Division | City of London and County of London | |

## Mounted units

The original mounted brigades were:
* Eastern Mounted Brigade
* Highland Mounted Brigade
* London Mounted Brigade
* Lowland Mounted Brigade
* North Midland Mounted Brigade
* Nottinghamshire and Derbyshire Mounted Brigade
* South Eastern Mounted Brigade
* 1st South Midland Mounted Brigade
* 2nd South Midland Mounted Brigade
* South Wales Mounted Brigade
* 1st South Western Mounted Brigade
* 2nd South Western Mounted Brigade
* Welsh Border Mounted Brigade
* Yorkshire Mounted Brigade
A number of yeomanry divisions were also formed:
| Name | Formed | Theatre | Notes |
| 1st Mounted Division | August 1914 | Home defence | Became the 1st Cyclist Division in July 1916. Disbanded November 1916. |
| 2nd Mounted Division | September 1914 | Gallipoli Campaign | Fought dismounted at Gallipoli. Disbanded January 1916. |
| 3rd Mounted Division | March 1915 | Home defence | Formed as the second-line 2/2nd Mounted Division. Renamed to 3rd Mounted Division March 1916. Renamed to 1st Mounted Division July 1916. Renamed to Cyclist Division September 1917. Disbanded June 1919. |
| 4th Mounted Division | March 1916 | Home defence | Renamed to 2nd Cyclist Division July 1916. Disbanded November 1916. |
| Yeomanry Mounted Division | July 1917 | Sinai and Palestine Campaign | Lost its yeomanry affiliation April 1918, becoming an Indian division and renamed to 1st Mounted Division. |
| 74th (Yeomanry) Division | April 1917 | Sinai and Palestine Campaign Western Front | Formed from dismounted yeomanry. Transferred to France May 1918. Disbanded July 1919. |

## Other divisions

Also considered divisions of the Territorial Force were:
* 71st, 72nd and 73rd Divisions – formed late 1916 as Home Service divisions; all broken up early 1918.
* 75th Division – mixed Territorial Force and Indian Army division formed in June 1917.