The book by the famous American historian Stephen E. Ambrose is dedicated to Operation Overlord - the landing and invasion of Allied forces in Nazi-occupied France in 1944. Its scale is amazing: in one day, 175 thousand people in full combat gear were transferred across the English Channel and 50 thousand units of equipment - from motorcycles to armored bulldozers. 5,333 ships and about 11 thousand aircraft took part in this. W. Churchill called the landing of expeditionary forces “the most difficult and complex operation in the history of mankind,” the preparation of which took two years.