Up until 1984, when it began to use the continental or NATO system, the UK operated its own system, with three branches:
- G Branch. The General branch, responsible for operations, intelligence and training.
- A Branch. The Administration branch, responsible for all aspects of personnel management.
- Q Branch. The Quartermaster branch, responsible for logistic and equipment support.
Positions were labelled as follows:
- GSO1 General Staff Officer (Grade 1). The chief of staff, ranked a lieutenant colonel or colonel. He was in charge of the General Staff Branch, responsible for training, intelligence, planning operations and directing the battle as it progressed. Most orders from the General Officer Commanding (GOC) were actually written up and signed by the GSO1.
- GSO2 General Staff Officer (Grade 2) Ranked a major.
- GSO3 General Staff Officer (Grade 3) Ranked a captain.
The positions may also be styled GSO I, GSO II, GSO III.
"The British did have staff officers as far back as the Crimean War working in these three cells but staff work was looked at with great disdain in the British Army and only became acceptable after the terrible hardships of the Crimean war, brought on by disorganization" The General Staff in Britain was formed in 1905, and reorganized again in 1908. Unlike the Prussian staff system, the British Army was thought too small to support separate staff and command career streams. Officers would typically alternate between staff and command. Beevor, Inside the British Army, says instead that the terrible cleavages between staff and line units caused by the enormous losses during First World War trench warfare meant that British senior officers decided that from thenceforth all officers would rotate between staff and line responsibilities, preventing the development of a separate general staff corps.
In the British system, "staff" are outranked by "command" officers. The staff cannot in theory (and largely in practice) say "no" to a subordinate unit; only the Commander has that ability. The principal staff officers at any HQ were always outranked by the subordinate commanders:
- Lieutenant Colonels commanding battalions or units in a brigade outrank the Brigade Major and the Deputy Assistant Adjutant & Quartermaster General
- Brigadiers commanding brigades in a division outrank the Colonel GS and Colonel AQ
- Major Generals commanding divisions outrank the Brigadier GS and Assistant Adjutant General and Assistant Quartermaster General at a Corps HQ
This ensured a clear chain of command, and reinforced the idea that staff do not command, but exercise control on behalf of their commander. By contrast, in the American system, commanders are frequently outranked by staff officers. For example, within a battalion, the S3 is a major while company commanders are captains.
G branch (operations) plans and executes operations. The senior staff officer in Brigade HQ was a Brigade Major (BM, rank Major), who coordinated the HQ. While the BM was responsible for the entire HQ, he concentrated mainly on "G" operational matters. A deputy BM GSO III generally looked after non-operational matters. Under the BM were several GSO III (rank captain) officers:
- Operations (the senior captain)
- Liaison. The Liaison section often had several Lieutenants attached from the brigade's combat units.
A branch handled all personnel matters: awards, postings, promotions, medical, chaplains, military police and so forth. There were usually one or two GSO III officers in A branch.
Q Branch handled logistics, supply, transport, clothing, maintenance. There was usually one GSO III officer, with a learner Captain or Lieutenant, and several advisors, all Captains:
- BRASCO (Brigade Royal Army Service Corps Officer)
- BOO (Brigade Ordnance Officer)
- BEME (Brigade Electrical and Mechanical Engineer Officer)
A and Q branches might be combined under a DAA&QMG (Deputy Assistant Adjutant and Quartermaster General, rank Major).
G Branch was under the Colonel GS (a Lieutenant-Colonel).
The combined "A" and "Q" staffs was headed by a Colonel AQ, who was assisted by an AA&QMG (Assistant Adjutant and Quartermaster General, rank Lieutenant Colonel).
Members of the G staff:
- A GSO II, acting as deputy to the GSO I. He was responsible for the preparation of orders and instructions as directed by the GSO I; the general organization and working of the "G" office; detailing of duty officers at the Div HQ; coordinating arrangements for moving the Main HQ; details of movement by road in consultation with the DAAG and DAQMG; and general policy regarding HQ defence and the preparation and promulgation of HQ standing orders. (In an Armoured Division Headquarters, the GSO II was responsible for the Division Tactical HQ and the above duties were done by the GSO III (Operations).)
- The GSO III (Operations) was the understudy to the GSO II; he maintained the situation map; prepared situation reports; supervised the acknowledgment register; maintained the command matrix; prepared orders for the move of the Orders Group; and prepared orders for the move of the Division's Main HQ.
- The GSO III (Operations)(Chemical Warfare) was responsible for all matters dealing with Chemical Warfare that affected the division; coordinated courses; was responsible for the camouflage policy; maintained the war diary; prepared and maintained location statements; received and distributed codes, call sign lists and other signals information from the divisional signals; coordinated traffic control and organization of routes in the divisional forward area under the GSO II and APM; was understudy to the GSO III (Operations) on all matters less CW.
- The GSO III (Intelligence) coordinated all intelligence training and work in the division; coordinated the collection and collation of information about enemy dispositions, methods and intentions; prepared daily intelligence summaries; coordinated interpretation of air photographs with the Army Photographic Interpretation Section (APIS); effected liaison with the APIS, the field security office and the Intelligence Officer, Royal Artillery (at CRA); and was responsible for briefing and handling of press correspondents.
- The GSO III (Liaison) coordinated the work of the Liaison Officers, was responsible for the division information room and served as an understudy to the GSO III (Operations).
G branch was headed by the Brigadier General Staff (BGS, rank Brigadier). The BGS was usually superior to the AAG and AQMG, despite all three having the same rank.
A branch was headed by the Assistant Adjutant General (AAG, rank Brigadier). He was assisted by the Deputy Assistant Adjutant General (DAAG, rank Lieutenant Colonel).
Q branch was headed by the Assistant Quartermaster General (AQMG rank Brigadier).
The G staff for a corps might appear as below:
- Operations and Staff Duties:
- GSO I
- GSO II (Ops)
- GSO II (Ops)(CW)
- GSO II (SD)—Staff Duties
- 2 × GSO III (SD)
- GSO II (Int)
- 2 × GSO III (Int)
- GSO II (L)
- 3 × GSO III (L)
- Royal Artillery:
- GSO II (RA)
- GSO II (AA)
- GSO III (RA)