Essen is a city in west Germany, near to the Belgian border. It was an important area for steel and metal production, including arms and weaponry during the war, which is why it was bombed so heavily.
Stalingrad, a city in southern Russia, began in July 1942 and continued for seven months. It was a crucial turning point in the Second World War, breaking the offensive strength of the German army. It is estimated that a total of two million people were killed during the siege. The Russians managed to hold out, and finally encircled and destroyed the invading army in February 1943.