Fighter Command
   

Fighter Command was established on 14 July 1936 under the leadership of Air Marshal Sir Hugh Dowding as part of a complete reorganisation and expansion of the Royal Air Force in Britain Its headquarters was Bentley Priory at Stanmore, Middlesex. The Command was organised into a number of Groups, each of which was responsible for the defence of a geographical area. At the beginning of the Battle of Britain, 11 Group covered London and the south east of England and was commanded by Air Vice-Marshal Keith Park.

12 Group, led by Air Vice-Marshal Trafford Leigh-Mallory, controlled the Midlands, East Anglia and northern England upto south Yorkshire and Lancashire. 13 Group defended the rest of northern England, southern Scotland upto Glasgow and Edinburgh, Scapa Flow and Northern Ireland under the command of Air Vice-Marshal Richard Saul. 10 Group, to cover the south west of England and Wales, became operational later in July, commanded by Air Vice-Marshal Sir Quintin Brand.

Each Group was sub-divided into geographical sectors to facilitate tactical control. Each sector contained a main fighter airfield equipped with an operations room to control all the fighters in its area, together with extensive maintenance and repair facilities. The sector station would also command one or more forward satellite landing grounds which would be used to re-fuel aircraft or provide advanced readiness capability.

Fighter Command was the apex of a command and control network which unified the different elements of fighter aircraft, radar and ground defences into a complex system of defence which gave it a formidable striking power and effective operational flexibility. Bentley Priory was the heart of this system and it received information on incoming hostile aircraft, relayed on secure landlines from the radar stations, to its Filter Room. Once the direction of the plots was established, the relevant Group Operations Room was alerted, where the Group commander would decide which of his sectors would intercept. The sector station commanders then activated or "scrambled" the fighter squadrons.