The German High Command were in no doubt that an Allied invasion of France would take place in 1944.
After years of depleting the Western Front in order to strengthen the Eastern Front, it was imperative to try and get up to strength before any invasion took place.
By June 1944 there were up to 56 Divisions present on the Western Front, the strength of these divisions were not as great as they looked on paper, many were well below strength.

Army Group B in 1944 consisted of troops ranging from "very poor" quality to the might of the Waffen S.S.
Paratroop Divisions, who were very highly trained and Six Panzer Divisions.

Ten percent of the German army which faced the Allies in France were made up of foreign eastern Europeans, some of these men truly believed in German victory, but most were conscripted from the slave labour camps and were there under sufferance.
The Luftwaffe was non-existent and the Allied airforces virtually sealed off Normandy, making it almost impossible for reinforcements and supplies to reach the front line.
By June 18th. up to 40,000 officers and men from all ranks had been killed in action!
On the 17th. June, Rommel and Von Rundstedt met with Hitler and told him the battle for Normandy was lost.
Hitler did not agree!

On July 2nd. Von Rundstedt was retired on grounds of age and ill health.
One by one each of the High Command of Army Group B  was replaced, until eventually only Rommel remained from the original commanders at D-Day.
On July 17th. Rommel's staff car was attacked by two allied aircraft and he was seriously wounded.
July 20th. saw the plot to kill Hitler take place.
Rommel was arrested by the Gestapo and after interrogation he was told his option…."Commit suicide and save your family".
He was given a State Funeral, his death being announced as a result of his wounds.