The Special Reserve (Category b)

The Special Reserve was formed as part of the Haldane reforms of the army in 1908 as a way of building up a pool of trained men who could be mobilised in the event of emergency.

Most of its men were classified as belonging to “Category a” of the Special Reserve, but there was a smaller and specific “Category b”. This page offers an explanation.

“They [the Category b men] are an absolutely essential part of the Expeditionary Force, which will be incomplete without them” (Hansard, 12 March 1912)

Troops of the 1st Battalion, The King’s Own (Royal Lancaster Regiment), 12th Brigade, 4th Division, in the front trench at St. Marguerite, 22nd September 1914. The officer is Second Lieutenant R. C. Matthews, probably the CO of “A” Company. Some of the Special Reserve category b troops of the Royal Army Medical Corps are known to have served with the 12th Field Ambulance supporting this brigade.

Category b Special Reserve

Entry was only available to men serving with the Territorial Force who had completed preliminary recruit training and attended two or more annual training camps of 15 days each.

Category b was to be composed of men who were returned as supernumerary to the Territorial Force and who had undertaken to join the Special Reserve on mobilisation and to serve abroad. The terms of duty with the Special Reserve included undertaking liability for service overseas in the event of a national emergency.

Category b only applied to the Royal Army Medical Corps, Army Service Corps and Army Veterinary Corps, although recruiting problems led to some adjustment of this in 1909 (see below).

The man had to make a quarterly submission of a Life Certificate (Army Form D842), essentially to ensure that the authorities had an up to date address.

Problems with recruiting into Category b

Hansard, 9 March 1909:

“As to the eighth Question, we recruit for the Army Service Corps and the Army Medical Corps under the two different categories, known as category (a) (ordinary Special Reserve) and category (b) (men whom we recruit from the Territorial Army). Of the Army Service Corps under category (a) the establishment is 1,000, and the strength obtained so far is fifty; under category (b), the establishment is 2,500, and the strength, five; but recruiting for both these classes has only just been thrown open, category (a) last November, and, so far as category (b) is concerned, we expect these men to do one training with the Territorial Force before they join category (b). Therefore, as regards the number of men who can join category (b), you may practically say that the thing is not yet in working order. Then, with regard to the Army Medical Corps, in category (a) the establishment is 1,000, and the strength 657; and in category (b) the establishment is 3,000, and the strength, 183. The establishment of the Special Reserve Army Medical Corps has been revised because it has been decided to throw open to a certain number of men of the Regular Reserve of the Infantry an opportunity of becoming Reservists for the Army Medical Corps. We have a very large Reserve at the present time for the Infantry, and advantage has been taken of that to ask 1,000 men of the Infantry Regular Reserve whether they will go through a medical training course at Aldershot and undertake the duties of Army Medical Corps on mobilisation. That course has not begun yet, so we do not know what number of men will join. In reply to the last Question, we shall be very glad to table a return giving the figures for which the noble Duke asks.”


“Regulations of the Territorial Force and for County Associations 191, Appendix XX”  stated that each corps would set aside a sequence of numbers for issue to Category b men.

Men of Category b would be issued with numbers from the sequence but not notified of it until such time that they were mobilised. In the meantime they would continue to be known by their Territorial Force number.

The regulation also stated that “In the event of a man becoming non-effective for any cause after joining Category b of the Special Reserve, his [Special Reserve] number will be allotted to the man enlisted in his place”.


The men of Category b reported to their normal TF depot on 5 August 1914 and were very quickly issued with their SR numbers and posted to units of the regular army. It is known, for example, that men of the 1st, 2nd and 3rd South Midland Field Ambulances (RAMC) were sent to join the regular army’s 12th Field Ambulance and arrived on 8 August. Others went to 3rd Casualty Clearing Station. Men of the East Anglian Field Ambulances went to 11th Field Ambulance. Within days these units were in France, putting them amongst the earliest territorials to go overseas even if it was technically under Special Reserve terms.


Reserves and reservists

Royal Army Medical Corps