Why did the american soldiers invade Normandy in WW2?

The D-Day invasion took years of planning.

Allied leaders Franklin Roosevelt and Winston Churchill knew from the start of the war that a massive invasion of mainland Europe would be critical to relieve pressure from the Soviet army fighting the Nazis in the east.

the noble might have thought that the system was far because they had lot of things and riches and the serf would have thought that the feudal system was un fair because of the way they were treated.