Constituted as 451st Bombardment Group (Heavy) on 6 Apr 1943. Activated on 1 May 1943. Prepared for combat with B-24's. Moved to the Mediterranean theater, Nov 1943-Jan 1944, with the air echelon training in Algeria for several weeks before joining the remainder of the group in Italy. Operated with Fifteenth AF, Jan 1944-May 1945, functioning primarily as a strategic bombardment organization. Attacked such targets as oil refineries, marshalling yards, aircraft factories, bridges, and airfields in Italy, France, Germany, Czechoslovakia, Austria, Hungary, Rumania, Bulgaria, Albania, and Greece. Received a DUC for each of three missions: to an aircraft factory at Regensburg on 25 Feb 1944, to oil refineries and marshalling yards at Ploesti on 5 Apr 1944, and to an airdrome at Vienna on 23 Aug 1944; although encountering large numbers of enemy fighters and severe antiaircraft fire during each of these missions, the group fought its way through the opposition, destroyed many interceptors, and inflicted serious damage on the assigned targets.
