When we come to formations larger than a battalion, we find the system of control and command becoming less and less personal and direct, as in all such formations the commander works to a less or greater extent through his staff. Roughly speaking, the staff is of two divisions, the one consisting of the general staff branch and the other of the branch of the adjutant and quartermaster-general. Again speaking very generally, the general staff is charged with duties bearing directly on military operations, while officers of the adjutant and quartermaster-general's branch deal more with administrative questions. Officers of the general staff are known as general staff officers, while those of the other branch are called, for example, assistant or deputy-assistant adjutant or quartermaster-general, according to their several duties.
The formation in which distinct and separate units are first collected under one superior commander is known as a brigade. This, according to present establishment, consists of three battalions and a trench-mortar battery, the whole under a general officer called a brigadier-general, assisted by a staff of two officers--a brigade-major and a staff-captain. Since March, 1920, however, the title of brigadier-general has been altered to 'colonel-commandant'. The strength of a brigade is something over 3000 of all ranks. In a division, which is the next highest formation, and which is commanded by a major-general with a staff of three general staff officers and three officers belonging to the A.G. and Q.M.G. branch, we find the first appearance of a mixed force. It is not a force of 'all arms', as cavalry is not included, but, in addition to infantry (three brigades), it has a considerable strength in artillery, besides engineers and the necessary administrative troops. Two or more divisions, together with a cavalry regiment and certain other troops, form an 'army corps', and two or more corps go to make up an 'army'. These are not at present peace-time formations of the British army.
Of the administrative troops and services already mentioned, the Royal Army Service Corps provides for the material wants of the army both in the way of food and transport. It is organized in companies designated by numerals.