The group arrived at Gioia del Colle Airfield, Italy at the beginning of January 1944, although the air echelon remained at Telergma Airfield, Algeria until 20 January to conduct additional training. The group functioned primarily as a strategic bombing unit, attacking targets like oil refineries, marshalling yards, aircraft factories and airfields in Italy, Germany, France, Czechoslovakia, Austria, Bulgaria, Hungary, Romania, Greece and Albania. It earned a Distinguished Unit Citation during Big Week for an attack on a Messerschmitt aircraft factory at Regensburg, Germany on 25 February 1944. It added oak leaf clusters to this award for an attack on oil refineries and marshalling yards at Ploesti, Romania on 5 April 1944 and on Markersdorf-Haindorf Airfield near Vienna, Austria on 23 August 1944. On each of these missions the 451st was opposed by large numbers of enemy interceptor aircraft and heavy flak, but fought its way through to inflict serious damage on the targets and destroy many enemy aircraft.