Rundstedt Reveals Allies Knew His Atlantic Wall Better

In the summer of 1945, a captured German field marshal sat in a small office at Wilton Park in Buckinghamshire and admitted something that should have been impossible. Gerd von Rundstedt, the man who had commanded the entire Atlantic Wall from his headquarters outside Paris, told his British interrogators that the Allies had probably known more about the wall than the men who built it. This investigation traces the full story behind that admission, from the BBC's secret 1942 appeal for British holiday postcards of the French coast, to the Free French Centurie network and the housepainter René Duchez who walked out of a German Organisation Todt office in Caen with a master plan of the Normandy fortifications hidden behind a mirror, to the midget submarine X-20 that carried Royal Engineers officer Logan Scott Bowden within four hundred yards of Omaha Beach to collect sand samples in January 1944. Drawing on declassified interrogation transcripts, the Liddell Hart Centre at King's College London, the Foreign Military Studies of Bodo Zimmermann, and the surviving BIGOT maps issued at Norfolk House in St James's Square, this video examines how Allied photographic interpreters at RAF Medmenham, French Resistance agents along the Channel coast, and the Combined Operations Pilotage Parties together built a unified picture of the wall that no German general ever assembled. It also looks at the structural reasons the German command in the West, fragmented between Rundstedt, Rommel, Hitler, the Kriegsmarine under Krancke, the Luftwaffe under Sperrle, the SS under Himmler, and the Organisation Todt under Speer, could not see its own fortifications whole. By June 6, 1944, the lieutenants and sergeants coming ashore at Vierville, Colleville, and La Rivière carried maps with the spacing of every beach obstacle, the field of fire of every observed bunker, and the location of every minefield, real and dummy. The story behind those maps, and behind Rundstedt's quiet final admission, is one of the most remarkable intelligence achievements of the Second World War. WW2 history, D-Day, Atlantic Wall, Operation Overlord, Normandy 1944, Gerd von Rundstedt, Erwin Rommel, French Resistance, René Duchez, BIGOT maps, Operation Postage Able, Operation Fortitude, RAF Medmenham, Combined Operations Pilotage Parties, Allied intelligence, Wehrmacht command, Norfolk House SHAEF, Centurie network, Confrérie Notre Dame, Colonel Rémy, Logan Scott Bowden, Wilton Park CSDIC, Liddell Hart interrogations, June 6 1944, World War 2 documentary.


Sources used in this investigation:
📚 Primary archives & official records

Liddell Hart Centre for Military Archives, King's College London (Rundstedt interrogation papers): https://archives.kingscollections.org
Royal Air Force Museum (Rundstedt interrogation extract on Overlord air action): https://collections.rafmuseum.org.uk/collection/object/object-163398/
Royal Engineers Museum Archive M1833 (Operation Postage Able operational orders and reports)
U.S. Army Foreign Military Studies, Bodo Zimmermann MS #B-308, "OB West (Atlantic Wall to Siegfried Line)": https://www.worldcat.org/title/30520411

📖 Operation Postage Able & COPP reconnaissance

COPP Survey (definitive archive on Logan Scott Bowden, Bruce Ogden Smith, X-20 mission): https://www.coppsurvey.uk/january-1944
COPP Survey, Normandy Operation Neptune hub: https://www.coppsurvey.uk/normandy-hub
COPP Survey, The D-Day Scientists: https://www.coppsurvey.uk/the-dday-scientists

🇫🇷 René Duchez & Centurie Network

AASSDN (French Special Services veterans association) tribute to René Duchez: https://aassdn.org/amicale/hommage-a-rene-duchez/
Préfecture du Calvados, official portrait of René Duchez: https://www.calvados.gouv.fr/Actions-de-l-Etat/Ressources-historiques-et-memorielles/Seconde-Guerre-mondiale-ressources-historiques-et-sites-memoriels/Portraits/Resistants-veterans-acteurs-et-temoins-du-Debarquement-et-de-la-bataille-de-Normandie/Rene-DUCHEZ
Mémoire et Espoirs de la Résistance, René Duchez: https://www.memoresist.org/resistant/rene-duchez/
Société Mémoires de Guerre Caen, OCM-Caen network: http://sgmcaen.free.fr/resistance/ocm.htm

🏛 Atlantic Wall, German command & D-Day intelligence

Warfare History Network, "Building the Atlantic Wall": https://warfarehistorynetwork.com/article/building-the-atlantic-wall/
Kansas State University Eisenhower Lecture, "The Convenient Opponent: The Wehrmacht and D-Day": https://www.k-state.edu/history/research/eisenlecture/6lecture.html
U.S. Naval History & Heritage Command, "Rommel and the Atlantic Wall" interrogation of Vizeadmiral Ruge and Generalleutnant Dihm: https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/r/rommel-atlantic-wall.html
Imperial War Museums, The German Response to D-Day: https://www.iwm.org.uk/history/the-german-response-to-d-day