For the defender, the initial scene that an invasion presents is one of confusion, and Overlord generated more than most. The Germans had made studies of previous Allied invasion tactics and had concluded that their amphibious landings took place only at dawn and in good weather. Due to the prevailing storm in the English Channel, the permanent state of alert under which Army Group B had been living for several months became more relaxed. Indeed, as the airborne landings were taking place, many of the senior commanding officers on the ground were not at their posts, but were instead in Rennes, at a war games meeting designed to combat a theoretical invasion. Unknown to almost everyone, Generalfeldmarschall Erwin Rommel was not even in France at all. Convinced that his efforts to defeat an invasion would be hampered by the fact that none of the S.S. Panzer Divisions, sitting in reserve, could be moved by him without Hitler's direct approval, Rommel had returned to Germany to ask that these Divisions be handed over to him. He was though, at the moment of the assault, not with Hitler, but at home with his wife, whose birthday was on the 6th June.
The first sign that something was happening in Normandy came when the German telephones ceased to work. The lines had been blown by the French Resistance, who had been called into action by coded messages on radio broadcasts. There was, however, nothing unusual in this as such attacks by the Underground were commonplace. If there had been more time for a clearer picture of these events to present itself, before the invasion took place, then a good deal of suspicion over the extent of this activity may have arisen. Far from just the standard destruction of mere telegraph poles and railway lines, other, more significant targets were being destroyed. One of these was a pipeline which carried petrol to Sword Beach, which would have fueled a device to set the sea on fire in the event of an invasion.
As the British and American paratroopers began to land, various reports drifted in to the Germans, but their confused nature could not even confirm for certain that this was an airborne invasion, never mind where it was concentrated, in what strength, or whether this was anything more than a small-scale commando raid. There had been so many false alarms in the past that the tendency was to err on the side of caution. Generalmajor Reichert, commander of the 711th Division, had even come face to face with British soldiers when two pathfinders landed on top of his headquarters and were immediately taken prisoner, but faced with only two men it was impossible for him to conclude whether this was the invasion or an opportunistic raid on his Headquarters.
The confusion was heightened by a British invention named "Rupert", a small dummy which, in the dark and from a distance, looked every bit like a paratrooper. These dummies, which contained a series of explosives that were triggered as they hit the ground, were deliberately dropped on the top of German troop concentrations in order to create the impression that they were under attack, a feeling which was greatly reinforced by small groups of very brave SAS soldiers who accompanied these drops. It was, in these first vital hours, impossible for the Germans to identify the Rupert drops from the real ones, and so they were fooled into moving reinforcements in the wrong direction.
To create the impression that no airborne attack was taking place at all, many of the aircraft delivering the real paratroopers also carried a small load of 20 lb bombs, which were used against various targets in the area of the landings so that it would appear that the activity in the air heralded nothing more than a routine bombing raid.
Both the British and American parachute drops were wildly scattered, some men landed many miles from their drop zone. Although this was an obvious disadvantage to them, it was of little benefit to the German commanders either. Small groups of lost paratroopers were roaming all over Normandy, attacking any enemy positions that they could find. As a consequence the Germans were receiving reports of airborne raids in areas miles from where the 6th, 82nd and 101st Airborne Divisions were operating, and this also led to reinforcements again being sent to the wrong places.
Slowly, however, the reality of the situation was realised and it was clear that a landing of some form was taking place. Few supposed, however, that this could be anything more than a feint. It had been anticipated that the Allies might launch a small-scale diversionary attack in Normandy in the hope of distracting attention from the real landings, which were still expected to take place in the Pas-de-Calais area.