4 Group was originally formed in October 1918 at the Seaplane Experimental Station, Felixstowe just before the end of the First World War and disbanded a year later in 1919.

On 29 June 1937 the headquarters were relocated at RAF Linton-on-Ouse, Yorkshire when 4 Group took over a number of stations and squadrons from No.

By this time the group had shrunk to six squadrons and the equipment had been standardised to the Armstrong Whitworth Whitley.

4 Group, equipped with the Vickers Wellington and carried out night bombing operations from May 1941 until February 1942.

On 24 July 1941, 4 Group dropped 2,000 lb bombs on the Scharnhorst and Gneisenau and helped to keep these battle-cruisers locked in Brest until 12 February 1942.

By January 1942 the Group had grown considerably and was made out of the following flying units, which were in full conversion from the Whitley to the Vickers Wellington medium and Handley Page Halifax heavy bomber: On 30/31 May 1942 No.

In July 1944 the group looked like this, having pretty much standardised on the Halifax B.Mk.III: Prior to the invasion of Normandy in June 1944 intense attacks began on French marshalling yards and gun emplacements on the French coast, troop concentrations and V-weapon sites, reaching a peak in August when 3,629 sorties were flown.

4 Group undertook urgent transport work and in little more than one week ferried 432,840 gallons of petrol to the British Second Army during Operation Market Garden.

In 1945, 4 Group attacked targets at Hanover, Magdeburg, Stuttgart, Cologne, Munster and Osnabrück plus the Sterkrade, Wanne-Eickel, Bottrop and many other synthetic-oil centres, bombing by day and night.