Prior to the outbreak of the First World War, the Regular Infantry consisted of four Guards Regiments (the Welsh Guards were not formed until 1915) and sixty nine Infantry Regiments. Both the Guards and the Infantry Regiments normally consisted of two active Battalions and one Reserve Battalion. With the exception of the Guards one of these active Battalions would serve overseas and one would remain in Great Britain. Both Guards Battalions normally stayed in Great Britain.
The Reserve Battalions would normally stay at the Regiment’s home depot training new soldiers and supplying drafts to the two active Battalions. There were, however, exceptions to this and some Regiments had four active Battalions and two Reserve Battalions, in this case two of the active Battalions would serve overseas and two would remain in Great Britain. Each of the Reserve Battalions would supply drafts to the active Battalions.
The Battalions would be numbered, the active Battalions first and then the Reserve Battalion: i.e. 1st and 2nd Bn Welsh Regiment. 3rd (Reserve) Bn Welsh Regiment.
Many of the Infantry Regiments, but not the Guards or Irish Regiments, also had Territorial Force Battalions, these were part-time soldiers similar to todays Territorial Army. Each Battalion trained its own soldiers therefore there were no Reserve Territorial Force Battalions. The Territorial Force Battalions were numbered after the Regular Reserve Battalions and often had second titles linking them with the home town or county of the Battalion: i.e. 4th (Renfrewshire) Bn Argyll and Sutherland Highlanders.
In addition to the Guards and Regular Infantry Regiments there were also ten Territorial Force Regiments. These were entirely made up of part-time soldiers and in all other aspects were the same as the other Territorial Force Battalions.
The Regular active Battalions serving in Great Britain and all the Territorial Force Battalions were grouped into Brigades and Divisions. A Brigade consisted of four Battalions and a Division consisted of three Brigades. The Regular Divisions were made up of Battalions from any the Regiments but the Territorial Force Divisions were normally made up from Battalions within a certain area.
The Regular Divisions and Brigades were numbered and the Territorial Force Division and Brigades were named (the Territorial Force Division and Brigades were numbered in May 1915 keeping their names as a second title): e.g.
1st Division consisting of:
1st (Guards) Brigade
East Anglian Division consisting of:
The outbreak of the First World War brought some changes to the Infantry Regiments. The Regular Battalions remained as they were but within the Territorial Force Battalions some changes were made.
When a man joined the Territorial Force, he had a choice of service he could volunteer for. He could volunteer for service at home, and if required overseas, or just for Home Service. The rates of pay were different. Men volunteering for both home and overseas were paid more than the Home Service volunteers.
Because the Territorial Force Battalions had men of both categories, the Battalions had to split forming second line Battalions just after the war started, the second line Battalions being for Home Service. The Territorial Force Battalions were now given fractional numbers, i.e. 1/4th Bn (first fourth) for duties overseas and 2/4th Bn (second fourth) for Home Service (although many 2nd line Battalions were sent overseas later during the war).
By June 1915 most of the Territorial Force Battalions had formed a 3rd line. The role of this 3rd line was to supply reinforcements to the Battalions of the 1st and 2nd lines. These 3rd line Battalions also had a fractional designation, a 3/ followed by the number of the parent Battalion. The 3rd line Battalions were formed in the autumn of 1915 into groups, each group relating to one of the pre-war Territorial Force Divisions. The 3rd line Battalions dropped the fractional numbers in April 1916 and became Reserve Battalions Territorial Force, e.g. 4th Reserve Bn Black Watch Territorial Force. The Territorial Reserve Battalions of each Regiment were amalgamated to form one Reserve Battalion, or in the case of the large Regiments two Battalions.The groups which had been formed, now became 14 Reserve Brigades Territorial Force. The Territorial Reserve Battalions remained this way for the rest of the war.Some 3rd line Battalions were sent overseas, when this was the case a 4th line Battalion was formed and this took the role of the 3rd line Battalion explained here.
A number of other Territorial Force Battalions were raised during the summer of 1915, these Battalions were known as Provisional Battalions. These were made up from personnel of the 2nd and 3rd line Battalions not available for overseas service and soldiers of low medical categories. By 1916 there were 41 Provisional Battalions serving in ten Provisional Brigades. In November 1916 the 6th, 8th and 9th Provisional Brigades were used to form the Home Service Divisions (71st-73rd). Most of these Provisional Battalions were disbanded when the Graduated Battalions were posted to the Home Service Divisions. The remaining Provisional Battalions became numbered Home Service Territorial Battalions of the Infantry Regiments on 01 January 1917.
The remaining seven Provisional Brigades were numbered 221st-227th, the Brigades were later called Mixed Brigades and were stationed on the east coast for the remainder of the war.
When Lord Kitchener became Secretary of State for War, he immediately stated that we must be prepared for a war lasting three years and would require an Army of seventy Divisions.
On 7 August a campaign was started to recruit an additional 100,000 men between the ages of 19 and 30. The response was overwhelming and the first 100,000 men had been recruited within a few days. By the middle of September 500,000 men had enlisted. It was decided by Kitchener not to use the framework of the Territorial Force to expand the Army, but to create new armies separate from the Regulars and the Territorials.
More than 500 New Army Battalions were raised as part of the existing Regiments, the New Army Battalions were numbered consecutively after the existing Battalions in the Regiment, they were distinguished by the word ‘Service’ in brackets after their number. The types of Service Battalions raised were:
a. The Battalions raised during August and September 1914. These Battalions formed the first three Kitchener Armies also known as K1 (9th-14th Divisions), K2 (15th-20th Divisions) and K3 (21st-26th Divisions).
b. A 4th Kitchener Army (K4 30th-35th Divisions) was raised in the Autumn of 1914 from the surplus personnel from the Regular Reserve and Extra Reserve Battalions. Later, to supply reinforcements for K1-K3, it was decided to break up K4 and convert the Infantry Battalions to Reserve Battalions, this was done by April 1915. The Reserve Battalions were to train recruits and supply drafts to the Battalions of K1-K3. These Battalions were known as 2nd Reserve Battalions, by 1 September 1916 all the 2nd Reserve Battalions had been absorbed into the Training Reserve.
c. At the same time as the first four Armies were being raised (K1-K4), a number of Service Battalions were being raised by committees from Cities, Towns, organisations and individuals. The expense of raising, clothing, housing and feeding these Battalions were met by the committees until they were taken over by the War Office in 1915. The War Office then refunded the committee their expenses. These Battalions were known as Locally Raised Battalions. The Battalions then went on to supply most of the Infantry for the new 4th Army. They used the Divisional numbers (30th-35th) from the old 4th Army (K4). A 5th New Army was raised (36th-40th Divisions) also made up from Locally Raised Battalions. The Locally Raised Battalions had an additional title in brackets showing their connection with the area, town or organisation which raised them (commonly known as the ‘Pals’ Battalions).
d. The Locally Raised Service Battalions formed Depot Companies, and in 1915 these Companies were grouped to form Local Reserve Battalions. These Battalions were numbered after the parent Battalion. The role of these Local Reserve Battalions was to supply reinforcements to the Locally Raised Service Battalions. On 1 September 1916 all the Local Reserve Battalions were absorbed into the Training Reserve.
e. A few more Service and Reserve Battalions were raised in 1915 and 1916 in addition to the four categories above. The Battalions were raised by converting dismounted Yeomanry Regiments into Infantry. In the summer of 1918 about twenty Garrison Battalions and other Battalions were renamed Service Battalions. They were used to reconstitute the 14th, 16th, 40th and 59th Divisions which had been reduced to Cadre. These Battalions had no connection with the Service Battalions of the New Armies raised at the beginning of the war.
In 1915 two kinds of Reserve Battalions were formed from the New Army Service Battalions. The role of these Battalions was to supply the Service Battalions with reinforcements.
In April 1915 the 75 Battalions of the 4th New Army (K4) were converted into 2nd Reserve Battalions. In the summer of 1915 further Reserve Battalions were formed when the Depot Companies of the Locally Raised Battalions were organised into Reserve Battalions. A total of 68 Local Reserve Battalions were raised. All these one hundred and forty three Reserve Battalions were formed into twenty four Reserve Brigades.
In 1916 the Training Reserve was formed when it was found that the New Army Reserve Battalions were unable to cope with the number of recruits coming into the Army after the introduction of conscription. The role of the Training Reserve was to train new recruits and despatch drafts to the Service Battalions serving overseas.
The 2nd Reserve and Local Reserve Battalions discarded their Regimental designations and became numbered Battalions of the Training Reserve from 1st-112th. The twenty four Reserve Brigades became Training Reserve Brigades. Some of the old Reserve Battalions were absorbed into the Training Reserve Battalions when the Training Reserve was formed, hence the reduction in number of Battalions from 143 to 112.
The Reserve and Extra Reserve Battalions of the Regular Army were not affected by these changes. Also, the Reserve Battalions of the Territorial Force were unaffected.
The Irish Regiments had no 2nd Reserve Battalions and there were only six Local Reserve Battalions. The six Local Reserve Battalions were used to supply drafts to the 36th (Ulster) Division. These Battalions did not form part of the Training Reserve.
A further reorganisation of the Training Reserve took place in 1917, the Battalions became more specialised in the training they carried out. In May 1917, 14 Battalions were designated Young Soldier Battalions. These Battalions took in and trained soldiers aged 18 years and one month. After completing basic training the young soldiers were posted in Company strength to Graduated Battalions. Twenty-eight Graduated Battalions were formed and linked in pairs to the Young Soldier Battalions, they would be used for Home Service while the soldiers within the Battalion finished their recruit training.
The Graduated Battalions were numbered from 201st onwards and posted to the eight Home Service Divisions, they were eventually increased in number until there were 46. The number of the Young Soldier Battalions was increased to 23. These Battalions were organised in to six Reserve Brigades.
On 27 October 1917, the Graduated and Young Soldier Battalions were allotted to 23 Infantry Regiments. The Battalions were numbered 51st and 52nd for the Graduated Battalions and 53rd for the Young Soldier Battalion.
The Home Service Divisions were reduced from eight to six, all of their Battalions except one was now a Graduated Battalion.
The remaining Training Reserve Battalions continued serving until the end of the war when they formed six recruit reception Battalions and four Battalions for training Machine Gun Corps recruits. The remaining Battalions were disbanded.
The Officer Training Corps (O.T.C.) was formed in 1908 and was based at the universities and public schools. Between August 1914 and March 1915 20,577 temporary commissions had been granted to former members of the O.T.C. This just about exhausted the supply of men that had served with the O.T.C. So in January 1915 it was decided to grant commissions to suitable men from the ranks on recommendation from their commanding officers. The training of these men was carried out by the O.T.C. In February 1916 the system of officer training was changed and Officer Cadet units were formed. The courses in these Cadet Battalions lasted four months before a successful candidate received his temporary commission. By June 1916 there were about a dozen Cadet Battalions and by July 1917 there were 23 Battalions around the country. By the end of the war over 73,000 officers had been trained by the Officer Cadet Bns.