# British infantry brigades of the First World War

During the First World War, 259 infantry brigades were raised by the British Army, two by the Royal Navy, and one from the Royal Marines. Of these brigades, fifty-three were held in reserve or only used for training, while another nine only served in British India.
The pre war regular army only had eighteen infantry brigades, with another forty-five serving with the reserve Territorial Force (TF). Once war was declared, the regular army was expanded first by volunteers and then conscripts for what became known as Kitchener's Army. At the same time, volunteers for the TF formed second line formations.
Three infantry brigades served with a division, mostly the same one throughout the war, but some did serve for short periods with another division. At the start of the war, four infantry battalions along with a small headquarters formed a brigade; but, by 1918, with the number of casualties mounting, the brigade was reduced to three battalions. During the same time, the firepower of a brigade was increased by the assignment of more machine guns. Eventually, as the war progressed, a brigade had its own machine gun company and a trench mortar battery assigned.

## Background

At the outbreak of the war in August 1914, the British regular army was a small professional force. It consisted of 247,432 regular troops organised into four Guards, 69 line infantry and 31 cavalry regiments, along with artillery and other support arms. The regular Army was supported by the Territorial Force, and by reservists. In August 1914, there were three forms of reserves. The Army Reserve of retired soldiers was 145,350 strong. The Special Reserve had another 64,000 men and was a form of part-time soldiering, similar to the Territorial Force. The National Reserve had some 215,000 men, who were on a register which was maintained by Territorial Force County Associations; these men had military experience, but no other reserve obligation. The regulars and reserves—at least on paper—totalled a mobilised force of almost 700,000 men, although only 150,000 men were immediately available to be formed into the British Expeditionary Force.

### Pre war regular army

After 1907, the regular British Army, serving at home, was grouped into six divisions, each of three brigades numbered 1st–18th. Following the declaration of war, four infantry battalions, which had been intended to defend the lines of communication, were brigaded together as the 19th Brigade. Near the end of 1914, when regular army battalions returned to Europe from serving around the British Empire, they formed the 7th and 8th Division, with the 20th–25th brigades. As the war progressed, three more regular army divisions were formed the 27th, 28th and 29th, with their brigades being numbered from 80th–88th.

### Territorial Force

The reserve formations of the Territorial Force comprised fourteen divisions, each of three brigades, while another three brigades were independent formations intended for coastal defence. They were unnumbered until August 1915, and took the name of the region with which they were affiliated, or the name of the regiments that supplied their battalions. When the brigades were given numbers, they became the 125th–234th brigades. As a home defence organisation, their men could not be sent overseas against their wishes. After war was declared, almost to a man the Territorial Force volunteered to serve overseas, so a second line Territorial Force was recruited, virtually a mirror image of the first line divisions and brigades. For example, the Northumbrian Division, had the Northumberland, York and Durham and the Durham Light Infantry Brigades. The second line 2nd Northumbrian Division, had the 2nd Northumberland, 2nd York and Durham and the 2nd Durham Light Infantry Brigades. Volunteers for the second line Territorial Force had the same terms and conditions as the first line, and could not be sent overseas unless they agreed to do so.

### Kitchener's Army

The third part of the British Army was the New Army, also known as Kitchener's Army. Recruits for the New Armies were technically part of the regular army, serving for three years or until the end of the war. The first of the New Armies comprised the 9th–14th divisions, with the 26th–43rd brigades. The second New Army comprised the 15th–20th divisions, with the 44th–61st brigades. The third comprised the 21st–26th divisions, with the 62nd–79th brigades. The fourth and fifth were the Pals battalions of the 30th–35th divisions, with the 89th–106th brigades and the 37th–42nd divisions, with the 110th–136th brigades. The last New Army was the sixth, comprising the 36th–41st divisions, with the 107th–124th brigades.

### Infantry brigade composition

At the start of the First World War French, Russian and German divisions consisted of two brigades each of which were made up of two regiments. Each regiment had three battalions, except the Russians which had four, which meant that in total there were around 6,000 men in the brigade. The British Army was different. Its divisions consisted of three brigades, with each brigade having slightly over 4,000 men in four battalions, plus support troops, under the command of a brigadier general.
The 1914 British infantry brigade comprised a small headquarters and four infantry battalions, with two heavy machine guns per battalion. Over the course of the war, the composition of the infantry brigades gradually changed, and there was an increased emphasis upon providing them with their own organic fire support. By 1916, each brigade had a Vickers machine gun company and a mortar battery with eight Stokes Mortars. The machine gun companies were later withdrawn and combined into a divisional machine gun battalion. By 1918, the brigade formation had been reduced to three battalions. However, each battalion now had thirty-six Lewis machine guns, making a total of 108 in the brigade.
Several brigades that served away from the Western Front and other main theatres of operations, had a different composition. The 228th Brigade, which served with the command of the Greek Crete Division, had a Royal Engineers signal section and a Royal Army Medical Corps field ambulance attached. Other brigades that served in the British Salonika Army, had a Section Ammunition Column attached. Brigades that served in the Mesopotamia Campaign had their own supply and transport columns of the Army Service Corps. One brigade, the 226th Mixed, was unique in the respect that it was the only infantry brigade with its own artillery, having two batteries from the Royal Garrison Artillery assigned.
In the trench warfare on the Western Front, an infantry brigade's defensive responsibilities depended upon where they were at the time. On 21 March 1918, the first day of the German spring offensive, the 173rd Brigade was responsible for 5,000 yards (4,600 m) of the front line. In 1918, the British Army was responsible for 126 miles (203 km) of the Western Front. The forty-two brigades, fourteen divisions, of the First Army had to defend 33 miles (53 km). The thirty-six brigades, twelve divisions, of the Second Army 23 miles (37 km). The forty-two brigades, fourteen divisions, of the Third Army 28 miles (45 km). The thirty-six brigades, twelve divisions, of the Fifth Army possibly had the hardest task with 42 miles (68 km) of front to defend.
Within the brigade a typical deployment was one battalion in the front line, with the other two in reserve, about 2 to 3 miles (3.2 to 4.8 km) back. The forward battalion had several sections manning outposts in the front trench with two companies manning strong points behind them. The third company was in reserve to act as a counter-attacking force and the fourth company was resting. Two brigades of a division would be deployed forward with the third brigade in reserve.

## List of brigades

| Brigade | Superior HQ | First arrived at the front | Location | Notes |
| 1st Guards Brigade | Guards Division | August 1915 | Western Front | Formed by redesignation of 4th (Guards) Brigade after transferring complete from the 1st Division to the Guards Division. |
| 1st (Guards) Brigade | 1st Division | August 1914 | Western Front | Prewar Regular Army formation. Redesignated 1st Brigade after the Guards battalions left for the Guards Division. |
| 1st Brigade | 1st Division | August 1915 | Western Front | Formed by redesignation of 1st (Guards) Brigade after the Guards battalions left for the Guards Division. |
| 1st (Royal Naval) Brigade | 63rd (Royal Naval) Division | October 1914 | Western Front | Formed from Royal Navy reservists. Re-designated 1st Brigade in August 1915, then disbanded July 1916. |
| 1st Provisional Brigade | Southern Army | | Home service | Formed from Home Service men of Territorials, attached to 67th (2nd Home Counties) Division. Became 221st Mixed Brigade. |
| 1st Reserve Brigade | Northern Command | | Home service | Converted from original 89th Brigade |
| 2/1st London Brigade | 58th (2/1st London) Division | December 1914 | Malta | Left the Division for Malta. |
| 2nd Guards Brigade | Guards Division | August 1915 | Western Front | Formed from the Regular Army. |
| 2nd Brigade | 1st Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 2nd (Royal Naval) Brigade | 63rd (Royal Naval) Division | October 1914 | Western Front | Formed from Royal Navy reservists. Broken up July 1915, and reformed August 1915 as 2nd Brigade. Renamed the 2nd (Royal Naval) Brigade and then 189th Brigade July 1916. |
| 2nd Provisional Brigade | Southern Army Eastern Command | | Home service | Formed from Home Service men of Territorials. Became 222nd Mixed Brigade. |
| 2nd Reserve Brigade | Northern Command | | Home service | Converted from original 90th Brigade |
| 3rd Guards Brigade | Guards Division | August 1915 | Western Front | Formed from the Regular Army. |
| 3rd Brigade | 1st Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 3rd (Royal Marine) Brigade | 63rd (Royal Naval) Division | August 1914 | Western Front | Formed from surplus Royal Marine reserves, with no berths on ships available. Disbanded August 1915, until May 1916. Re-designated 1st (Royal Naval) Brigade and 188th Brigade in July 1916. |
| 3rd Provisional Brigade | Northern Army | | Home service | Formed from Home Service men of Territorials, attached to 69th (2nd East Anglian) Division. Became 223rd Mixed Brigade. |
| 3rd Reserve Brigade | Northern Command | | Home service | Converted from original 91st Brigade |
| 4th (Guards) Brigade | 2nd Division | August 1914 | Western Front | Prewar Regular Army formation. Renumbered 1st Guards Brigade August 1915. |
| 4th Guards Brigade | 31st Division | February 1918 | Western Front | Formed from three battalions of the Guards Division when divisions on the Western Front were reduced from twelve to nine battalions. |
| 4th Provisional Brigade | Northern Army | | Home service | Formed from Home Service men of Territorials, attached to 64th (2nd Highland) Division. Became 224th Mixed Brigade. |
| 4th Reserve Brigade | Eastern Command | | Home service | Converted from original 92nd Brigade |
| 5th Brigade | 2nd Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 5th Provisional Brigade | Northern Army | | Home service | Formed from Home Service men of Territorials. Became 225th Mixed Brigade. |
| 5th Reserve Brigade | Eastern Command | | Home service | Converted from original 93rd Brigade |
| 6th Brigade | 2nd Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 6th Provisional Brigade | Northern Army | | Home service | Formed from Home Service men of Territorials. Became 71st Division. |
| 6th Reserve Brigade | Eastern Command | | Home service | Converted from original 94th Brigade |
| 7th Brigade | 3rd Division 25th Division | August 1914 | Western Front | Prewar Regular Army formation. Joined 25th Division October 1915. |
| 7th Provisional Brigade | Southern Army | | Home service | Formed from Home Service men of Territorials. Became 226th Mixed Brigade. |
| 7th Reserve Brigade | Eastern Command | | Home service | Converted from original 95th Brigade |
| 8th Brigade | 3rd Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 8th Provisional Brigade | Northern Army | | Home service | Formed from Home Service men of Territorials. Became 72nd Division. |
| 8th Reserve Brigade | Southern Command | | Home service | Converted from original 96th Brigade |
| 9th Brigade | 3rd Division 28th Division | August 1914 | Western Front | Prewar Regular Army formation. Attached to 28th Division between February and April 1915. |
| 9th Provisional Brigade | Southern Army | | Home service | Formed from Home Service men of Territorials. Became 73rd Division. |
| 9th Reserve Brigade | Scottish Command | | Home service | Converted from original 97th Brigade |
| 10th Brigade | 4th Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 10th Provisional Brigade | Southern Army | | Home service | Formed from Home Service men of Territorials. Became 227th Mixed Brigade. |
| 10th Reserve Brigade | Eastern Command | | Home service | Converted from original 98th Brigade |
| 11th Brigade | 4th Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 11th Reserve Brigade | Western Command | | Home service | Converted from original 99th Brigade |
| 12th Brigade | 4th Division 36th (Ulster) | August 1914 | Western Front | Prewar Regular Army formation. Attached to 36th (Ulster) Division between November 1915 and February 1916. |
| 12th Reserve Brigade | Scottish Command | | Home service | Converted from original 100th Brigade |
| 13th Brigade | 5th Division | August 1914 | Western Front | Prewar Regular Army formation. Attached to 28th Division between February 1915 and April 1915. Also fought in the Italian Campaign. |
| 13th Reserve Brigade | Western Command | | Home service | Converted from original 101st Brigade |
| 14th Brigade | 5th Division 32nd Division | August 1914 | Western Front | Prewar Regular Army formation. Transferred to 32nd Division December 1915. |
| 14th Reserve Brigade | Western Command | | Home service | Converted from original 102nd Brigade |
| 15th Brigade | 5th Division | August 1914 | Western Front | Prewar Regular Army formation. Attached to 28th Division between March and April 1915. Also fought in the Italian Campaign. |
| 15th Reserve Brigade | Irish Command | | Home service | Converted from original 103rd Brigade |
| 16th Brigade | 6th Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 16th Reserve Brigade | Western Command | | Home service | Converted from original 104th Brigade |
| 17th Brigade | 6th Division 24th Division | August 1914 | Western Front | Prewar Regular Army formation. Transferred to 24th Division October 1915. |
| 17th Reserve Brigade | Western Command | | Home service | Converted from original 105th Brigade |
| 18th Brigade | 6th Division | August 1914 | Western Front | Prewar Regular Army formation. |
| 18th Reserve Brigade | Scottish Command | | Home service | Converted from original 106th Brigade |
| 19th Brigade | 6th Division 27th Division 2nd Division 33rd Division | August 1914 | Western Front | Formed from Army Troops of the BEF. GHQ Troops until October 1914, joined 27th Division May 1915. Transferred to 2nd Division August 1915, then 33rd Division November 1915. |
| 19th Reserve Brigade | Northern Command | | Home service | |
| 20th Brigade | 7th Division | October 1914 | Western Front | Formed from the Regular Army. Also fought in the Italian Campaign. |
| 20th Reserve Brigade | Northern Command | | Home service | |
| 21st Brigade | 7th Division 30th Division | October 1914 | Western Front | Formed from the Regular Army. Transferred to 30th Division December 1915 |
| 21st Reserve Brigade | Northern Command | | Home service | |
| 22nd Brigade | 7th Division | October 1914 | Western Front | Formed from the Regular Army. Also fought in the Italian Campaign. |
| 22nd Reserve Brigade | Southern Command | | Home service | |
| 23rd Brigade | 8th Division | November 1914 | Western Front | Formed from the Regular Army. |
| 23rd Reserve Brigade | Eastern Command | | Home service | |
| 24th Brigade | 8th Division 23rd Division | November 1914 | Western Front | Formed from the Regular Army. Transferred to 23rd Division October 1916 to July 1916. |
| 24th Reserve Brigade | Eastern Command | | Home service | |
| 25th Brigade | 8th Division | November 1914 | Western Front | Formed from the Regular Army. |
| 26th Brigade | 9th (Scottish) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 26th Reserve Brigade | London District | | Home service | |
| 27th Brigade | 9th (Scottish) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 28th Brigade | 9th (Scottish) Division | May 1915 | Western Front | Kitchener's Army brigade. Disbanded May 1916 reformed September 1918. |
| 28th Reserve Brigade | | | Home service | |
| 29th Brigade | 10th (Irish) Division | August 1915 | Gallipoli campaign | Kitchener's Army brigade. Also fought on the Macedonian Front and in the Sinai and Palestine Campaign. |
| 30th Brigade | 10th (Irish) Division | August 1915 | Gallipoli Campaign | Kitchener's Army brigade. Also fought on the Macedonian Front and in the Sinai and Palestine Campaign. |
| 31st Brigade | 10th (Irish) Division | August 1915 | Gallipoli Campaign | Kitchener's Army brigade. Also fought on the Macedonian Front and in the Sinai and Palestine Campaign. |
| 32nd Brigade | 11th (Northern) Division | August 1915 | Gallipoli Campaign | Kitchener's Army brigade. Also fought on the Western Front. |
| 33rd Brigade | 11th (Northern) Division 2nd Division | August 1915 | Gallipoli campaign | Kitchener's Army brigade. Transferred to 2nd Division November 1915. Also fought on the Western Front. |
| 34th Brigade | 11th (Northern) Division | August 1915 | Gallipoli campaign | Kitchener's Army brigade. Also fought on the Western Front. |
| 35th Brigade | 12th (Eastern) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 36th Brigade | 12th (Eastern) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 37th Brigade | 12th (Eastern) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 38th Brigade | 13th (Western) Division | June 1915 | Gallipoli campaign | Kitchener's Army brigade. Also fought in the Mesopotamia Campaign. |
| 39th Brigade | 13th (Western) Division | June 1915 | Gallipoli campaign | Kitchener's Army brigade. Also fought in the Mesopotamia Campaign. Attached Dunsterforce 1918. |
| 40th Brigade | 13th (Western) Division | June 1915 | Gallipoli campaign | Kitchener's Army brigade. Also fought in the Mesopotamia Campaign. |
| 41st Brigade | 14th (Light) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 42nd Brigade | 14th (Light) Division | May 1915 | Western Front | Kitchener's Army brigade. |
| 43rd Brigade | 14th (Light) Division | May 1915 | Western Front | Kitchener's Army brigade. Formed from Light Infantry battalions. |
| 44th Brigade | 15th (Scottish) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 45th Brigade | 15th (Scottish) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 46th Brigade | 15th (Scottish) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 47th Brigade | 16th (Irish) Division | December 1915 | Western Front | Kitchener's Army brigade. |
| 48th Brigade | 16th (Irish) Division | December 1915 | Western Front | Kitchener's Army brigade. |
| 49th Brigade | 16th (Irish) Division | December 1915 | Western Front | Kitchener's Army brigade. |
| 50th Brigade | 17th (Northern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 51st Brigade | 17th (Northern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 52nd Brigade | 17th (Northern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 53rd Brigade | 18th (Eastern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 54th Brigade | 18th (Eastern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 55th Brigade | 18th (Eastern) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 56th Brigade | 19th (Western) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 57th Brigade | 19th (Western) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 58th Brigade | 19th (Western) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 59th Brigade | 20th (Light) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 60th Brigade | 20th (Light) Division | July 1915 | Western Front | Kitchener's Army brigade. |
| 61st Brigade | 20th (Light) Division | July 1915 | Western Front | Kitchener's Army brigade. Formed from Light Infantry battalions. |
| 62nd Brigade | 21st Division | September 1915 | Western Front | Kitchener's Army brigade. |
| 63rd Brigade | 21st Division 37th Division | September 1915 | Western Front | Kitchener's Army brigade. Transferred to the 37th Division July 1916. |
| 64th Brigade | 21st Division | September 1915 | Western Front | Kitchener's Army brigade. |
| 65th Brigade | 22nd Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 66th Brigade | 22nd Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 67th Brigade | 22nd Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 68th Brigade | 23rd Division | August 1915 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. |
| 69th Brigade | 23rd Division | August 1915 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. |
| 70th Brigade | 23rd Division 8th Division | August 1915 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. Transferred to 8th Division October 1915 to July 1916. |
| 71st Brigade | 24th Division 6th Division | September 1915 | Western Front | Kitchener's Army brigade. Transferred to 6th Division October 1915. |
| 72nd Brigade | 24th Division | September 1915 | Western Front | Kitchener's Army brigade. |
| 73rd Brigade | 24th Division | September 1915 | Western Front | Kitchener's Army brigade. |
| 74th Brigade | 25th Division | September 1915 | Western Front | Kitchener's Army brigade. |
| 75th Brigade | 25th Division | September 1915 | Western Front | Kitchener's Army brigade. Renumbered as 236th Brigade and new 75th Brigade formed September 1918. |
| 76th Brigade | 25th Division 3rd Division | September 1915 | Western Front | Kitchener's Army brigade. Joined 3rd Division October 1915 |
| 77th Brigade | 26th Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 78th Brigade | 26th Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 79th Brigade | 26th Division | September 1915 | Western Front | Kitchener's Army brigade. Also fought on the Macedonian Front. |
| 80th Brigade | 27th Division | December 1914 | Western Front | Formed from the Regular Army. Also fought on the Macedonian Front. |
| 81st Brigade | 27th Division | December 1914 | Western Front | Formed from the Regular Army. Also fought on the Macedonian Front. |
| 82nd Brigade | 27th Division | December 1914 | Western Front | Formed from the Regular Army. Also fought on the Macedonian Front. |
| 83rd Brigade | 28th Division 5th Division | January 1915 | Western Front | Formed from the Regular Army. Transferred to 5th Division between March and April 1915. Also fought on the Macedonian Front. |
| 84th Brigade | 28th Division 5th Division | January 1915 | Western Front | Formed from the Regular Army. Transferred to 5th Division between February and April 1915. Also fought on the Macedonian Front. |
| 85th Brigade | 28th Division 3rd Division | January 1915 | Western Front | Formed from the Regular Army. Transferred to 3rd Division between February and April 1915. Also fought on the Macedonian Front. |
| 86th Brigade | 29th Division | April 1915 | Gallipoli campaign | Formed from the Regular Army. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 87th Brigade | 29th Division | April 1915 | Gallipoli campaign | Formed from the Regular Army. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 88th Brigade | 29th Division | April 1915 | Gallipoli Campaign | Formed from the Regular Army. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 89th Brigade | 30th Division | November 1915 | Western Front | Kitchener's Army brigade. Formed from King's (Liverpool Regiment) battalions. |
| 90th Brigade | 30th Division | November 1915 | Western Front | Kitchener's Army brigade. Formed from Manchester Regiment battalions. |
| 91st Brigade | 30th Division 7th Division | November 1915 | Western Front | Kitchener's Army brigade. Formed from Manchester Regiment battalions. Also fought in the Italian Campaign. Transferred to 7th Division December 1915 |
| 92nd Brigade | 31st Division | December 1915 | Egypt, Western Front | Kitchener's Army brigade, formed from East Yorkshire Regiment battalions. Following heavy casualties in April 1918 the 92nd and 93rd Brigades were amalgamated as the 92nd Composite Brigade. However they were reformed soon after. |
| 93rd Brigade | 31st Division | December 1915 | Egypt, Western Front | Kitchener's Army brigade. Following heavy casualties in April 1918 the 92nd and 93rd Brigades were amalgamated as the 92nd Composite Brigade. However they were reformed soon after. |
| 94th Brigade | 31st Division | December 1915 | Egypt, Western Front | Kitchener's Army brigade. Broken up February and reformed May and June 1918 by units of the 74th (Yeomanry) Division, and re-designated 94th (Yeomanry) Brigade. |
| 95th Brigade | 32nd Division 5th Division | November 1915 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. Transferred to 5th Division December 1915. |
| 96th Brigade | 32nd Division | November 1915 | Western Front | Kitchener's Army brigade. |
| 97th Brigade | 32nd Division | November 1915 | Western Front | Kitchener's Army brigade. |
| 98th Brigade | 33rd Division | November 1915 | Western Front | Kitchener's Army brigade, formed from Public Schools Battalions of the Royal Fusiliers. |
| 99th Brigade | 33rd Division 2nd Division | November 1915 | Western Front | Kitchener's Army brigade, formed from Royal Fusiliers battalions. Left to join 2nd Division in November 1915 |
| 100th Brigade | 33rd Division | November 1915 | Western Front | Kitchener's Army brigade. |
| 101st Brigade | 34th Division | January 1916 | Western Front | Kitchener's Army brigade. |
| 102nd (Tyneside Scottish) Brigade | 34th Division 37th Division | January 1916 | Western Front | Kitchener's Army brigade. Formed from Northumberland Fusiliers battalions. Attached to 37th Division July to August 1916, following heavy casualties incurred on the First day on the Somme. |
| 103rd (Tyneside Irish) Brigade | 34th Division 37th Division | January 1916 | Western Front | Kitchener's Army brigade. Formed from Northumberland Fusiliers battalions. Attached to 37th Division July to August 1916, following heavy casualties incurred on the First day on the Somme. |
| 104th Brigade | 35th Division | January 1916 | Western Front | Kitchener's Army brigade. |
| 105th Brigade | 35th Division | January 1916 | Western Front | Kitchener's Army brigade. |
| 106th Brigade | 35th Division | January 1916 | Western Front | Kitchener's Army brigade. |
| 107th Brigade | 36th (Ulster) Division 4th Division | October 1915 | Western Front | Kitchener's Army brigade. Attached to 4th Division between November 1915 and February 1916. Formed from Royal Irish Rifles battalions. |
| 108th Brigade | 36th (Ulster) Division | October 1915 | Western Front | Kitchener's Army brigade. |
| 109th Brigade | 36th (Ulster) Division | October 1915 | Western Front | Kitchener's Army brigade. |
| 110th Brigade | 37th Division 21st Division | August 1915 | Western Front | Kitchener's Army brigade, formed from Leicestershire Regiment battalions. Transferred to 21st Division July 1916. |
| 111th Brigade | 37th Division 34th Division | August 1915 | Western Front | Kitchener's Army brigade. Attached from the 37th Division between July and August 1916. |
| 112th Brigade | 37th Division 34th Division | August 1915 | Western Front | Kitchener's Army brigade. Attached from the 37th Division between July and August 1916. |
| 113th Brigade | 38th (Welsh) Division | November 1915 | Western Front | Kitchener's Army brigade, formed from Royal Welsh Fusiliers battalions. |
| 114th Brigade | 38th (Welsh) Division | November 1915 | Western Front | Kitchener's Army brigade. Formed from Welsh Regiment battalions. |
| 115th Brigade | 38th (Welsh) Division | November 1915 | Western Front | Kitchener's Army brigade. |
| 116th Brigade | 39th Division | March 1916 | Western Front | Kitchener's Army brigade. |
| 117th Brigade | 39th Division | March 1916 | Western Front | Kitchener's Army brigade. |
| 118th Brigade | 39th Division | March 1916 | Western Front | Kitchener's Army brigade. |
| 119th Brigade | 40th Division | June 1916 | Western Front | Kitchener's Army brigade. Also known as the Welsh Bantam Brigade. |
| 120th Brigade | 40th Division | June 1916 | Western Front | Kitchener's Army brigade. |
| 121st Brigade | 40th Division | June 1916 | Western Front | Kitchener's Army brigade. |
| 122nd Brigade | 41st Division | May 1916 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. |
| 123rd Brigade | 41st Division | May 1916 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. |
| 124th Brigade | 41st Division | May 1916 | Western Front | Kitchener's Army brigade. Also fought in the Italian Campaign. |
| 125th (Lancashire Fusiliers) Brigade | 42nd (East Lancashire) Division | September 1916 | Sinai and Palestine Campaign | First line Territorial brigade. Formed from Lancashire Fusiliers battalions. Also fought in the Gallipoli Campaign and on the Western Front. |
| 126th (East Lancashire) Brigade | 42nd (East Lancashire) Division | September 1916 | Sinai and Palestine Campaign | First line Territorial brigade. Also fought in the Gallipoli Campaign and on the Western Front. |
| 127th (Manchester) Brigade | 42nd (East Lancashire) Division | September 1916 | Sainai and Palestine Campaign | First line Territorial brigade. Formed from Manchester Regiment battalions. Also fought in the Gallipoli Campaign and on the Western Front. |
| 128th (Hampshire) Brigade | 43rd (Wessex) Division | October 1914 | British India | First line Territorial brigade. Formed from Hampshire Regiment battalions. |
| 129th (South Western) Brigade | 43rd (Wessex) Division | October 1914 | British India | First line Territorial brigade. |
| 130th (Devon and Cornwall) Brigade | 43rd (Wessex) Division | October 1914 | British India | First line Territorial brigade. |
| 131st (Surrey) Brigade | 44th (Home Counties) Division | October 1914 | British India | First line Territorial brigade. |
| 132nd (Middlesex) Brigade | 44th (Home Counties) Division | October 1914 | British India | First line Territorial brigade. |
| 133rd (Kent) Brigade | 44th (Home Counties) Division | October 1914 | British India | First line Territorial brigade. |
| 134th (2/1st Hampshire) Brigade | 45th (2nd Wessex) Division | December 1914 | British India | Second line Territorial brigade, that was disbanded in September 1917. |
| 135th (2/1st South Western) Brigade | 45th (2nd Wessex) Division | December 1914 | British India | Second line Territorial brigade. |
| 136th (2/1st Devon and Cornwall) Brigade | 45th (2nd Wessex) Division | December 1914 | British India | Second line Territorial brigade. |
| 137th (Staffordshire) Brigade | 46th (North Midland) Division | February 1915 | Western Front | First line Territorial brigade. |
| 138th (Lincoln and Leicester) Brigade | 46th (North Midland) Division | February 1915 | Western Front | First line Territorial brigade. |
| 139th (Sherwood Foresters) Brigade | 46th (North Midland) Division | February 1915 | Western Front | First line Territorial brigade. Formed from Sherwood Forester battalions. |
| 140th (4th London) Brigade | 47th (1/2nd London) Division | March 1915 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. |
| 141st (5th London) Brigade | 47th (1/2nd London) Division | March 1915 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. |
| 142nd (6th London) Brigade | 47th (1/2nd London) Division | March 1915 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. |
| 143rd (Warwickshire) Brigade | 48th (South Midland) Division | March 1915 | Western Front | First line Territorial brigade. Formed from Royal Warwickshire Regiment battalions. Also fought in the Italian Campaign. |
| 144th (Gloucester and Worcester) Brigade | 48th (South Midland) Division | March 1915 | Western Front | First line Territorial Army brigade. Also fought in the Italian Campaign. |
| 145th (South Midland) Brigade | 48th (South Midland) Division | March 1915 | Western Front | First line Territorial brigade. Also fought in the Italian Campaign. |
| 146th (West Riding) Brigade | 49th (West Riding) Division | April 1915 | Western Front | First line Territorial brigade. Formed from West Yorkshire Regiment battalions. |
| 147th (2nd West Riding) Brigade | 49th (West Riding) Division | April 1915 | Western Front | First line Territorial brigade. Formed from Duke of Wellington's Regiment battalions. |
| 148th (3rd West Riding) Brigade | 49th (West Riding) Division | April 1915 | Western Front | First line Territorial brigade. |
| 149th (Northumberland) Brigade | 50th (Northumbrian) Division | April 1915 | Western Front | First line Territorial brigade. Formed from Northumberland Fusiliers battalions. |
| 150th (York and Durham) Brigade | 50th (Northumbrian) Division | April 1915 | Western Front | First line Territorial brigade. |
| 151st (Durham Light Infantry) Brigade | 50th (Northumbrian) Division | April 1915 | Western Front | First line Territorial brigade. Formed from Durham Light Infantry battalions. |
| 152nd (1st Highland) Brigade | 51st (Highland) Division | May 1915 | Western Front | First line Territorial brigade. Known as the Seaforth and Cameron Brigade up to May 1915. |
| 153rd (2nd Highland) Brigade | 51st (Highland) Division | May 1915 | Western Front | First line Territorial brigade. Known as the Gordon Brigade up to May 1915. |
| 154th (3rd Highland) Brigade | 51st (Highland) Division | May 1915 | Western Front | First line Territorial brigade. Known as the Argyll and Sutherland Brigade up to May 1915. |
| 155th (South Scottish) Brigade | 52nd (Lowland) Division | May 1915 | Gallipoli campaign | First line Territorial brigade. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 156th (Scottish Rifles) Brigade | 52nd (Lowland) Division | May 1915 | Gallipoli campaign | First line Territorial brigade. Formed from Cameronians (Scottish Rifles) battalions. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 157th (Highland Light Infantry) Brigade | 52nd (Lowland) Division | May 1915 | Gallipoli campaign | First line Territorial brigade. Formed from Highland Light Infantry battalions. Also fought in the Sinai and Palestine Campaign and on the Western Front. |
| 158th (North Wales) Brigade | 53rd (Welsh) Division | July 1915 | Gallipoli campaign | First line Territorial brigade. Formed from Royal Welsh Fusiliers battalions. Also fought in the Sinai and Palestine Campaign. |
| 159th (Cheshire) Brigade | 53rd (Welsh) Division | July 1915 | Gallipoli campaign | First line Territorial brigade. Formed from Cheshire Regiment battalions. Also fought in the Sinai and Palestine Campaign. |
| 160th (South Wales) Brigade | 53rd (Welsh) Division | July 1915 | Gallipoli Campaign | First line Territorial brigade. Also fought in the Sinai and Palestine Campaign. |
| 161st (Essex) Brigade | 54th (East Anglian) Division | August 1915 | Gallipoli campaign | First line Territorial brigade. Formed from Essex Regiment battalions. Also fought in the Sinai and Palestine Campaign. |
| 162nd (East Midland) Brigade | 54th (East Anglian) Division | August 1915 | Gallipoli campaign | First line Territorial brigade. Also fought in the Sinai and Palestine Campaign. |
| 163rd (Norfolk and Suffolk) Brigade | 54th (East Anglian) Division | August 1915 | Gallipoli campaign | First line Territorial brigade. Also fought in the Sinai and Palestine Campaign. |
| 164th (North Lancashire) Brigade | 55th (West Lancashire) Division | January 1916 | Western Front | First line Territorial brigade. |
| 165th (Liverpool) Brigade | 55th (West Lancashire) Division | January 1916 | Western Front | First line Territorial brigade. Formed from King's Regiment (Liverpool) battalions. |
| 166th (South Lancashire) Brigade | 55th (West Lancashire) Division | January 1916 | Western Front | First line Territorial brigade. |
| 167th (1st London) Brigade | 56th (1st London) Division | January 1916 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. Left the division in September 1914 and rejoined in February 1916. |
| 168th (2nd London) Brigade | 56th (1st London) Division | January 1916 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. Broken up in November 1914 and reformed February 1916. |
| 169th (3rd London) Brigade | 56th (1st London) Division | January 1916 | Western Front | First line Territorial brigade. Formed from London Regiment battalions. Broken up April 1915 and reformed February 1916. |
| 170th (2/1st North Lancashire) Brigade | 57th (2nd West Lancashire) Division | February 1917 | Western Front | Second line Territorial brigade. |
| 171st (2/1st Liverpool) Brigade | 57th (2nd West Lancashire) Division | February 1917 | Western Front | Second line Territorial brigade. Formed from King's Regiment (Liverpool) battalions. |
| 172nd (2/1st South Lancashire) Brigade | 57th (2nd West Lancashire) Division | February 1917 | Western Front | Second line Territorial brigade. |
| 173rd (3/1st London) Brigade | 58th (2/1st London) Division | January 1917 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. |
| 174th (2/2nd London) Brigade | 58th (2/1st London) Division | January 1917 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. |
| 175th (2/3rd London) Brigade | 58th (2/1st London) Division | January 1917 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. Replaced 2/1st London Brigade in August 1915. |
| 176th (2/1st Staffordshire) Brigade | 59th (2nd North Midland) Division | February 1917 | Western Front | Second line Territorial brigade. |
| 177th (2/1st Lincoln and Leicester) Brigade | 59th (2nd North Midland) Division | February 1917 | Western Front | Second line Territorial brigade. |
| 178th (2/1st Nottinghamshire and Derbyshire) Brigade | 59th (2nd North Midland) Division | February 1917 | Western Front | Second line Territorial brigade. Formed from Sherwood Foresters battalions. |
| 179th (2/4th London) Brigade | 60th (2/2nd London) Division | June 1916 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. Also fought on the Macedonian Front. |
| 180th (2/5th London) Brigade | 60th (2/2nd London) Division | June 1916 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. |
| 181st (2/6th London) Brigade | 60th (2/2nd London) Division | June 1916 | Western Front | Second line Territorial brigade. Formed from London Regiment battalions. Also fought on the Macedonian Front. |
| 182nd (2nd Warwickshire) Brigade | 61st (2nd South Midland) Division | May 1916 | Western Front | Second line Territorial brigade. Formed from Royal Warwickshire Regiment battalions. |
| 183rd (2nd Gloucester and Worcester) Brigade | 61st (2nd South Midland) Division | May 1916 | Western Front | Second line Territorial brigade. |
| 184th (2nd South Midland) Brigade | 61st (2nd South Midland) Division | May 1916 | Western Front | Second line Territorial brigade. |
| 185th (2/1st West Riding) Brigade | 62nd (2nd West Riding) Division | January 1917 | Western Front | Second line Territorial brigade. Formed from West Yorkshire Regiment battalions. |
| 186th (2/2nd West Riding) Brigade | 62nd (2nd West Riding) Division | January 1917 | Western Front | Second line Territorial brigade. Formed from Duke of Wellington's Regiment battalions. |
| 187th (2/3rd West Riding) Brigade | 62nd (2nd West Riding) Division | January 1917 | Western Front | Second line Territorial brigade. |
| 188th (2/1st Northumberland) Brigade | 63rd (2nd Northumbrian) Division | | Home Service | Second line Territorial brigade, formed from Northumberland Fusiliers battalions. It was disbanded in November 1916 and its battalions were transferred 217th Brigade in 72nd Division |
| 188th Brigade | 63rd (Royal Naval) Division | July 1916 | Western Front | |
| 189th (2nd York and Durham) Brigade | 63rd (2nd Northumbrian) Division | | Home Service | Second line Territorial brigade. When the 63rd Division was disbanded in 1916 the brigade joined 73rd Division and was renumbered 220th Brigade. |
| 189th Brigade | 63rd (Royal Naval) Division | July 1916 | Western Front | |
| 190th (2nd Durham Light Infantry) Brigade | 63rd (2nd Northumbrian) Division | | Home Service | Second line Territorial brigade, formed from Durham Light Infantry battalions. When the 63rd Division was disbanded in 1916 the brigade joined 71st Division and was renumbered 214th Brigade. |
| 190th Brigade | 63rd (Royal Naval) Division | July 1916 | Western Front | |
| 191st (2nd Seaforth and Cameron Highlanders) Brigade | 64th (2nd Highland) Division | | Home Service | Second line Territorial brigade, formed from Seaforth Highlanders battalions. |
| 192nd (2nd Gordon Highlanders) Brigade | 64th (2nd Highland) Division | | Home Service | Second line Territorial brigade. Formed from Gordon Highlanders battalions. |
| 193rd (2nd Argyll and Sutherland Highlanders) Brigade | 64th (2nd Highland) Division | | Home Service | Second line Territorial brigade, formed from Argyll and Sutherland Highlanders battalions. |
| 194th (2/1st South Scottish) Brigade | 65th (2nd Lowland) Division | | Home Service | Second line Territorial brigade. |
| 195th (2/1st Scottish Rifles) Brigade | 65th (2nd Lowland) Division | | Home Service | Second line Territorial brigade, formed from four Cameronians (Scottish Rifles) battalions. |
| 196th (2/1st Highland Light Infantry) Brigade | 65th (2nd Lowland) Division | | Home Service | Second line Territorial brigade, formed from Highland Light Infantry battalions. |
| 197th (Lancashire Fusiliers) Brigade | 66th (2nd East Lancashire) Division | March 1917 | Western Front | Second line Territorial brigade, formed from Lancashire Fusiliers battalions. |
| 198th (East Lancashire) Brigade | 66th (2nd East Lancashire) Division | March 1917 | Western Front | Second line Territorial brigade. |
| 199th (Manchester) Brigade | 66th (2nd East Lancashire) Division | March 1917 | Western Front | Second line Territorial brigade, formed from Manchester Regiment battalions. |
| 200th (2/1st Surrey) Brigade | 67th (2nd Home Counties) Division | | Home Service | Second line Territorial brigade. Demobilised February 1918. |
| 201st (2/1st Middlesex) Brigade | 67th (2nd Home Counties) Division | | Home Service | Second line Territorial brigade, by Middlesex Regiment battalions. |
| 202nd (2/1st Kent) Brigade | 67th (2nd Home Counties) Division | | Home Service | Second line Territorial brigade. |
| 203rd (2nd North Wales) Brigade | 68th (2nd Welsh) Division | | Home Service | Second line Territorial brigade. |
| 204th (2nd Cheshire) Brigade | 68th (2nd Welsh) Division | | Home Service | Second line Territorial brigade. |
| 205th (2nd Welsh Border) Brigade | 68th (2nd Welsh) Division | | Home Service | Second line Territorial brigade. |
| 206th (2nd Essex) Brigade | 69th (2nd East Anglian) Division | | Home Service | Second line Territorial brigade. |
| 207th (2nd East Midland) Brigade | 69th (2nd East Anglian) Division | | Home Service | Second line Territorial brigade. |
| 208th (2nd Norfolk and Suffolk) Brigade | 69th (2nd East Anglian) Division | | Home Service | Second line Territorial brigade. |
| 209th Brigade | 70th Division | Never formed | | Number allocated but never formed |
| 210th Brigade | 70th Division | Never formed | | Number allocated but never formed |
| 211th Brigade | 70th Division | Never formed | | Number allocated but never formed |
| 212th Brigade | 71st Division | | Home Service | Had a dual role of training and home defence. Broken up March 1918. |
| 213th Brigade | 71st Division | | Home Service | Had a dual role of training and home defence. Broken up March 1918. |
| 214th Brigade | 71st Division 67th (2nd Home Counties) | | Home Service | Formed by renumbering 190th (2nd Durham Light Infantry) Brigade from disbanded 63rd (2nd Northumbrian) Division. Became a Special Brigade for service in Russia but remained in UK. Joined 67th Division, February 1918. |
| 215th Brigade | 72nd Division | | Home Service | Had a dual role of training and home defence. |
| 216th Brigade | 72nd Division | | Home Service | Had a dual role of training and home defence. |
| 217th Brigade | 72nd Division | | Home Service | Had a dual role of training and home defence. |
| 218th Brigade | 73rd Division | | Home Service | Had a dual role of training and home defence. |
| 219th Brigade | 73rd Division | | Home Service | Had a dual role of training and home defence. |
| 220th Brigade | 73rd Division | | Home Service | Formed by renumbering 189th (2nd York and Durham) Brigade from disbanded 63rd (2nd Northumbrian) Division |
| 221st Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role of training and home defence. |
| 222nd Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role training and home defence. |
| 223rd Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role of training and home defence. |
| 224th Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role of training and home defence. |
| 225th Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role of training and home defence. |
| 226th Mixed Brigade | 71st Division 67th (2nd Home Counties) | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role of training and home defence. |
| 227th Mixed Brigade | Not allocated | | Home Service | Formed from Provisional Battalions of Home Service Territorial personnel. Had a dual role training and home defence. |
| 228th Brigade | 28th Division | February 1917 | Western Front | Formed in February 1917 as Army Troops. Also fought on the Macedonian Front, it was associated with the 28th Division, then came under command of the Greek Crete Division from September to October 1918, when it was broken up. |
| 229th Brigade | 74th (Yeomanry) Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade, previously the 2nd Dismounted Brigade. Also fought on the Western Front. |
| 230th Brigade | 74th (Yeomanry) Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade, previously the 3rd Dismounted Brigade. Also fought on the Western Front. |
| 231st Brigade | 74th (Yeomanry) Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade, previously the 4th Dismounted Brigade. Also fought on the Western Front. |
| 232nd Brigade | 75th Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade. |
| 233rd Brigade | 75th Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade. |
| 234th Brigade | 75th Division | March 1917 | Sinai and Palestine Campaign | First line Territorial brigade. |
| 236th Brigade | Syren Force | November 1918 | North Russia | Formed from 75th Brigade |
| 237th Brigade | Syren Force | June 1918 | North Russia | |
| 238th Brigade | Independent | November 1918 | North Russia | |
| 242nd Brigade | 28th Division | March 1920 | Turkey | British Army of Occupation in Turkey after Armistice |
| Black Watch Brigade | Scottish Command | | Home service | First line Territorial brigade assigned to Coastal Defence duties, it was dissolved in early 1915 as its constituent battalions were posted to other formations. |
| 2/1st Black Watch Brigade | Scottish Command | | Home service | Second line Territorial brigade, duplicate of the Black Watch Brigade. It was dissolved in November 1915 as its constituent battalions were posted to other formations. |
| Lothian Brigade | Scottish Command | | Home service | First line Territorial brigade assigned to Coastal Defence duties. Became 1st Provisional Brigade. |
| South Wales Brigade | Western Command | | Home Service | First line Territorial brigade assigned as Army Troops and attached to the Welsh Division. It was dissolved in early 1915 as its constituent battalions were posted to other formations. |
| Highland Reserve Brigade | | | Home service | Territorial training brigade |
| Lowland Reserve Brigade | | | Home service | Territorial training brigade |
| West Lancashire Reserve Brigade | | | Home service | Territorial training brigade |
| East Lancashire Reserve Brigade | | | Home service | Territorial training brigade |
| Welsh Reserve Brigade | | | Home service | Territorial training brigade |
| Northumbrian Reserve Brigade | | | Home service | Territorial training brigade |
| West Riding Reserve Brigade | | | Home service | Territorial training brigade |
| North Midland Reserve Brigade | | | Home service | Territorial training brigade |
| South Midland Reserve Brigade | | | Home service | Territorial training brigade |
| East Anglian Reserve Brigade | | | Home service | Territorial training brigade |
| Wessex Reserve Brigade | | | Home service | Territorial training brigade |
| Home Counties Reserve Brigade | | | Home service | Territorial training brigade |
| 1st London Reserve Brigade | | | Home service | Territorial training brigade |
| 2nd London Reserve Brigade | | | Home service | Territorial training brigade |
| 3rd London Reserve Brigade | | | Home service | Territorial training brigade |