Improvements to fortifications along the Normandy coast had been undertaken under the leadership of `` Generalfeldmarschall '' Erwin Rommel beginning Process_start in October 1943 .

During the two weeks that the river was flooded , Hitler would not allow Preventing_or_letting Generalfeldmarschall Gerd von Rundstedt to withdraw Removing behind the Rhine , arguing that it would only delay Change_event_time the inevitable fight .