The great Allied invasion of Hitler’s fortress Europe, the largest amphibious operation in military history, began under General Dwight David Eisenhower at 6:00 a.m. as forces began to land along the coast of northern France, between Cherbourg and Le Havre. Within 24 hours, more than 4,000 ships discharged 176,000 soldiers on the shore. They were defended by 9,500 aircraft and 600 warships. 
 American forces captured Utah Beach as British forces overcame most of the German resistance and advanced toward Cannes. Serious resistance occurred only at Omaha Beach, where it took the forces until sundown to establish a toehold. Despite immense losses and difficulties in advancing, it was clear that the invasion had succeeded. Within 10 days, Field Marshal Rommel and General von Rundstedt knew there was no further point in attempting to hold the lines, and urged Hitler to authorize a retreat.