The "Atlantic Wall" was challenged by this event, which took place at sites nicknamed Sword, Gold, Juno, Utah, and Omaha.
Leonard Dawe was suspected of leaking information about this event due to the answer selection of his Daily Telegrapher crossword. To spread disinformation before this event, numerous dummy aircraft and airfields were created as part of Operation Fortitude. Its perpetrators modified large numbers of tanks with extendable ramps, flotation screens, or flamethrowers, known as Hobart's (*) Funnies. Artificial Mulberry harbors were developed for this event, which fortuitously happened when Erwin Rommel was on leave for his  wife's birthday. The "Atlantic Wall" was challenged by this event, which took place at sites nicknamed Sword, Gold, Juno, Utah, and Omaha. For 10 points, name this June, 6, 1944 Allied invasion of Europe
Leonard Dawe was suspected of leaking information about this event due to the answer selection of his Daily Telegrapher crossword.
D-Day [or Normandy landings; or Operation Overlord; or Operation Neptune; prompt on Allied invasion of Europe or similar answers]