Although many campaigns were fought in Asia and the Pacific, the major focus of the U.S. Army was always on the European Theater, where most its strength was ultimately deployed. U.S. forces saw action in the invasion of North Africa in November 1942, and the subsequent Tunisia Campaign in 1943. The U.S. Army participated in the Allied invasion of Sicily in July 1943, and then the Allied invasion of Italy in September. Hopes for a quick capture of Rome were frustrated by the Germans, who conducted a fighting withdrawal to the Gustav Line, which the landing at Anzio and the fighting at Monte Cassino in January 1944 failed to break. The Gustav Line was finally broken in May 1944, while Rome was captured on 4 June, and the Germans retreated to the Gothic Line in Northern Italy, where the Allies were held until they broke into the Po Valley in a successful offensive in April 1945.