in 1944 , major general leslie r. groves , jr. , director of the manhattan project , sent Sending major arthur v. peterson to brief general dwight d. eisenhower and his senior staff officers at the supreme headquarters allied expeditionary force ( shaef ) .

general dwight d. eisenhower was appointed commander of supreme headquarters allied expeditionary force ( shaef ) , and general bernard montgomery was named Name_conferral as commander of the 21st army group , which comprised Cause_to_be_included all the land forces involved in the invasion .