History books sometime call it The Longest Day, while some simply refer to it by a general operation term ’D-Day’ but Operation Overlord was the turning of the tide for the European war in the West.
Overlord might be the greatest battle, with all things considered, in the history of the modern world. Everyone knew it was coming. According to a joke of the time, the sheer concrete evidence of the impending invasion weighed so heavily on the British Isles that it should have sunk into the sea, if only they had not been held up by masses of barrage balloons.
In hundreds of hedge-bordered English fields, by late spring, were parks of camouflaged tanks, trucks, bulldozers, ducks, jeeps and self-propelled guns. Dozens of airfields were jammed to the fences with planes lined up beside the runways–more than 10,000 aircraft in all. Dozens of ports large and small were jammed with shipping–well over 5000 ships and landing crafts, including six battleships, twenty-two cruisers, and hundreds of destroyers, gunboats, corvettes and other fire-support crafts of what would become known as the Matchbox Fleet. More than 1 million troops especially trained for Overlord, half of them American and a half a mix of British or Canadian, organized in thirty-seven divisions for the amphibious assault.
It was an unprecedented concentration of power, and those who witnessed it happening believed it to be a manifestation of what would be by far the most complicated plan ever made for a single operation of war. And it was.
The invasion of Normandy on 6 June 1944 proved to be a complete tactical surprise. Rommel, the Allies soon learned after gaining control of the beaches, had not even been in France during the beginning of the twenty-four hours he had said would be decisive for the war. On the assumption that the predicted weather would make a cross-Channel operation impossible, he had returned to Germany on 4 June for his wife’s birthday and to confer with Hitler. He did not arrive back to his HQ until six o'clock that evening of D-Day.
Some 156,000 Allied troops had established themselves on nearly eighty square miles of Normandy soil at a casualty cost of around 11,000; and Allies dominance (or rather, supremacy) of the skies, immediate shipping capacity, and prepared build up made it unlikely that the Germans could push back the Overlord forces.
The feel of the war had changed. It was the Allies who were continually making gains, in both Europe and the Pacific, and the Axis who were suffering catastrophic losses.