The Battle of Stalingrad

Stalingrad, the largest battle in the entirety of World war 2.
This was one of the most important battles for the soviet union at the time. Stalingrad carried the name of the leader of the soviet union at the time, Joseph Stalin. Keeping Stalingrad under soviet union control was important to Stalin himself, simply because it was named after himself. If the Wehrmacht (German Army) took over Stalingrad, it would be an enormous blow to morale and would have probably doomed Russia.
Stalin needed to win this battle desperately, untrained Militia was formed in order to help beat the  Wehrmacht and women and children were required to dig trenches, Tanks where being manufactured and put out into to battle so quickly that they weren't even painted. Women played a pretty important role in this battle too, they would be enlisted as gunman, usually as scouts, snipers, or machine gunners. Stalin needed every possible unit in order to keep Stalingrad under soviet control.

September 12, the first German troops entered the city. The Germans were met with brutal force, and where forced into house to house fighting. this strategy of setting up so close to the Wehrmacht helped the Russians to avoid possible artillery fire and airstrikes because of their proximity to the Germans.
Stalin sent 2 of his best Generals, Georgy Zhukov and Vasily Chuikov to help lead the soldiers and militia against the Wehrmacht.  Zhukov prepared for a counter attack, while Vasilevksy attacked on the front with his '62nd army'. There were Huge numbers of casualties on both sides. In order to make sure that they didn't Lose Stalingrad, Stalin had Issued order No. 227 other wise referred to as "not one step backwards". The soviets had two layers in every front, the main front, and the supporting and last resort soldiers behind them.
If any soldier or officer was found deserting the battle, they would be automatically sent to a 'penal battalion' in the front line, this basically meant for sure death.
The soviets used their home turf advantage to its maximum potential. They used the trenches, under ground sewer systems and homes to get past and surprise the Wehrmacht. There was an immense amount of snipers on either side, the destroyed buildings of Stalingrad were great cover for these snipers.
The Germans where severely outmatched in when winter rolled around, the equipment that the Germans had where not meant for such severe cold. the Wehrmacht didn't have fur coats and head gear like the soviet union had. The Germans nearly froze to death.
The Germans had called upon Italian and Hungarian allies for help in taking over Stalingrad, but they had very low morale and where the first targets of the soviet union once they began to fight. 
The Soviets had separated and formed two fronts, one attacked the Hungarians from the north, and the other attacked the Italians from the south. Eventually, the Axis powers army was surrounded, but instead of being ordered to surrender by Hitler, they were sent more supplies via air planes in order to keep them fighting.
The Axis powers army was cut off from almost all outside help after the air support had stopped working. The army surrendered to the soviets in February 2 1943. There was about 1.25 million casualties in the battle for Stalingrad.

https://www.youtube.com/watch?v=gHkELWFqGKQ