The history of the 380th dates back to 28 October 1942 when the unit was established. The 380th Bombardment Group (Heavy) was activated on 3 November 1942 at Davis–Monthan Field, Arizona. Originally, the 380th Group consisted of four squadrons, the 528th, 529th Bombardment Squadron 529th, 530th, and 531st Bombardment Squadron. Shortly after being activated, the group moved to Biggs Field, Texas where it underwent extensive combat training. After completing training, the 380th moved to Lowry Field, Colorado to undergo final combat training. The 380th was part of Fifth Air Force, and was known as the "Flying Circus" and as the "King of the Heavies"