Because of diversions of groups to the invasion of North Africa, the bomber force in England had been limited in size to four groups of B-17s and two of B-24s until May 1943. At that time, and in conjunction with the Pointblank Directive to destroy the Luftwaffe in preparation for Operation Overlord, the B-17 force had expanded fourfold and was organized into the 1st and 4th Bombardment Wings (which due to their large size would soon be re-designated Bomb Divisions). The 1st Bombardment Wing, which included all of the original B-17 groups, was based in the English Midlands while the 4th Bombardment Wing stations were located in East Anglia.