Rundstedt had retired from the German Army after the FRITSCH- BLOMBERG crisis but returned to command Army Group A which invaded Poland in September 1939. In May 1940 he held the same command for the invasion of France and it was his Panzer spearhead which broke through at Sedan and cut off the British Expeditionary Force. He persuaded HITLER to allow Army Group A to halt its offensive and to leave the reduction of the Dunkirk pocket to the Luftwaffe. This crucial decision allowed the evacuation of the BEF. In 1941 Rundstedt was given command of Army Group South which moved through the Ukraine in September but was relieved of the command two months later when Hitler refused to allow him to withdraw. In 1942 he was reinstated and made Commander in Chief of the west and was responsible for the defense of Fortress Europe. When the Allies finally landed in Normandy, Rundstedt was caught unprepared: his troops were deployed over the Channel coast and his Panzer Divisions were well in the rear. On 1 July 1944 he was replaced by KLUGE, who was then dismissed on 17 August, and replaced by MODEL. Rundstedt was recalled in September but at that point there was little he could do to stop the Allied advance over northwest France. However he planned the Ardennes offensive, sometimes known as the Rundstedt offensive, in which he did not have much confidence. He retired in March 1945 after its failure, but to the end Hitler respected his judgment. It has been said that this was because Hitler was impressed by his aristocratic presence, and the Prussian military tradition which he represented.