In the spring of 1942 Hitler ordered his forces to advance southwards towards the USSR's oilfields in the Caucasus region. The Soviets resisted fiercely, suffering huge civilian and military casualties but by September the Germans had reached the edge of the city of Stalingrad on the River Volga.
German forces fought their way building by building towards the River Volga that bisects the city. They reached it in November 1942 but at a heavy cost of over 700,000 casualties and were left without supplies or reinforcements. As winter set in, the Soviets began to drive them back.
From November 1942 to January 1943 the Germans were worn down and encircled. German forces at Stalingrad surrendered at the beginning of February 1943 after the bloodiest battle in human history had resulted in almost 2 million casualties.
Stalingrad proved to be the turning point. Through the rest of 1943 the Red Army gradually regained territory from the German invaders.
In July 1943 they fought a gigantic tank battle at Kursk against the Germans and defeated them. From this point on the Red Army began to move steadily westwards.
German forces were finally driven away from Leningrad in January 1944.
By August 1944 the Red Army reached Poland and by early 1945 had moved into the eastern regions of Germany itself.
The last great battle came in April - May of 1945 when the Red Army reached Berlin. Once again the fighting became ferocious and the Germans were ordered to defend Berlin as stubbornly as the Soviets had defended their cities.
By 30th April Hitler was trapped in his bunker in the centre of Berlin and with the sound of Soviet troops only a few streets away he finally committed suicide and had his body burned in a hastily dug trench outside.
Germany finally surrendered to the Allied forces on May 9th 1945 bringing the war in Europe to an end.