The Workers' and Peasants' Red Army started out as the Soviet Union's revolutionary communist combat groups during the Russian Civil War of 1918–1922. It grew into the national army of the Soviet Union and by the 1930s, the Red Army was among the largest armies in history.
The Battle of Stalingrad and setbacks in the North Africa Campaign represented a major defeat for the Axis forces. In addition, the Axis forces were slowed by the bombings in Germany, the D-Day landings, and Operation Bagration.
Germany, and Europe as a whole, was almost totally dependent on foreign oil imports. In an attempt to resolve the persistent shortage, Germany launched Fall Blau (Case Blue), an offensive against the Caucasian oilfields, in June 1942. The Soviets launched a counter-offensive on 19 November and encircled the German armies, who were trapped in Stalingrad on 23 November. The Battle of Stalingrad lasted from July 17, 1942 to February 2, 1943, and was marked by brutality and disregard for military and civilian casualties, which placed it among the bloodiest battles in the history of warfare, with the higher estimates of combined casualties amounting to nearly two million. Hitler's refusal to allow a retreat led to the deaths of 200,000 German and Romanian soldiers; of those who surrendered on 31 January 1943, only 6,000 survivors returned to Germany after the war. Soviet forces continued to push the invaders westward after the failed German offensive at the Battle of Kursk, and by the end of 1943 the Germans had lost most of their territorial gains in the east.
In Libya,the Afrika Korps (the German expeditionary force in Libya and Tunisia during the North African Campaign) failed to break through the line at First Battle of El Alamein (July 1-27 1942), having suffered repercussions from the Battle of Stalingrad . Beginning in 1942, Allied bombing of Germany increased, severely damaging, among others, the cities of Hamburg, Cologne, and Dresden, killing thousands of civilians, and causing hardship for the survivors. Contemporary estimates of Nazi German military dead is 5.5 million.
In November 1942, the Wehrmacht and the Italian Army retreated to Tunisia, where they fought the Americans and the British in the Tunisia Campaign (November 17, 1942–May 13, 1943). The Allies invaded Sicily and Italy next, but met fierce resistance, particularly at Anzio (January 22,1944–June 5,1944) and Cassino (January 17, 1944–May 18,1944), and the campaign continued from mid-1943 to nearly the end of the war. In June 1944, American, British, and Canadian forces established the western front with the D-Day(June 6, 1944) landings in Normandy, France. After the successful Operation Bagration (June 22– August 19, 1944), the Soviet Army was in Poland; and in East Prussia, West Prussia, and Silesia the German populaces fled en masse, fearing Communist persecution, atrocity, and death.
In spring of 1945, the Soviet Army was at Berlin, and the United States and United Kingdom forces had conquered most of west Germany.