The battle of stalingrad was a battle between the germans and the soviet union. The battle started because of the german air force bombing Volga river and the city of stalingrad they attacked the city of stalingrad because it was a major industrial and communications center for the Soviet Union. After several long months of fighting the germans surrendered on feb 2nd 1943.
The battle of britain was a battle in britain from july 10th 1940 to october 31st 1940. After germany had conquered most of europe including france they only had great britain left to fight and conquer. Germany decided britain's Royal Air Force was a formidable opponent. so the Germans Decided to bomb there air ports and there runways so there planes couldn't take off.
D-Day was an invasion on the beaches of normandy on june 6th 1944. Germany had invaded france and tried to overtake the entire country of Europe Including Britain the allies were able to slow them down and they were now ready for an offensive attack. To prepare for the attack the allies accumulated soldiers and weapons in britain and before the invasion bombers were attacking germany forces left and right.