Formed in the United Kingdom during 1943 as the IX Air Support Command, its primary role was to provide close air support for the U.S. First Army. Re-designated as the IX Tactical Air Command in April 1944, its initial missions included interdicting transportation, disrupting communications and destroying warehouses and supply dumps in occupied France and the Low Countries in preparation for the Normandy Invasion in June. Targets included bridges, road junctions, railroads, airfields, radio towers and telephone exchanges. Engaging enemy aircraft in the air and establishing air superiority was another priority.
After the Normandy landings on 6 June 1944, IX Tactical Air Command Republic P-47 Thunderbolts concentrated on enemy targets in the Cotentin Peninsula area and afterward supported Operation Cobra, the breakout of Normandy. Paying particular attention to German forces in the Falaise-Argentan Gap, targets were expanded to include tanks, vehicles of all types and troop formations.