Few other military operations were as grueling and brutal as the Battle of Stalingrad.

The Soviets and the Nazis had a non-aggression pact through the early years of the war, but in 1941, Hitler invaded Russia. Although they failed to take the entire country, the Nazi’s made substantial territorial gains. August 1942 began the Soviet effort to retake it, and the fighting was ferocious and varied. Tank charges, trench warfare, dogfights, and tight-knit urban guerilla tactics all came into play, finally culminating in a Soviet victory by February 1943.

Here are some photos of those six months that proved to be the most pivotal period of World War II.