Germany invaded the Soviet Union in the summer of 1941 with a prejudice that they could defeat and take Moscow by October that year. The German army was advancing extremely rapidly with the deadly Blitzkrieg attack, and one million Soviet troops were conscripted to help protect the next target city, Kiev. Hitler assumed that because the German army had been so successful in all their past invasions, the inference was drawn that Moscow would easily fall under the command of the Nazis once they defeated it. Kiev eventually fell, and the Nazis launched a two-pronged attack on Stalingrad. The battle was brutally bloody, and the German army who were used to the ease of the Blitzkrieg attack were forced to confront their enemies in hand-to-hand combat. Stalin realized that ferociously standing their ground was doing very little to help the USSR push Germany back or even resist them, so the "Scorched Earth" policy was applied. This practice was quite effective because as the Soviet soldiers steadily retreated back into the endless stretch of land, they burned all the crops, dismantled factories and poisoned the wells so that the German army would not be able to use their supplies and get weak. Eventually, when all the German troops had exhausted their resources and were extremely weak, the USSR launched forward and chased the German army all the way back to Berlin which they overtook as well. .
The Soviets raised their red flag in Berlin on April 1945. This battle contrasts to the D-Day victory of the Allies because the total number of German casualties were much higher in the Battle of Stalingrad. This was significant because this event was considered the turning point of WWII. The Allies were almost giving up hope at this point in the war because of disastrous losses the German army caused them. However, the German army foolishly decided to take on the Russian winters and their vast army with limited winter supplies.