German estimate of Allied forces for Overlord

[paspartoo]

The Germans thought there were 80 Allied divisions in Britain prior to the Normandy invasion (not all operational though). Has anyone looked into which units they had correctly identified and what was false? I'm interested on whether their mistake was with US forces or British ones or both.

[Carl Schwamberger]

Both. I have a refrence on this somewhere here & will see if it is of use. From memory, the Brit/US deception organization compiled a OB of false units which was passed on to Germany via the Double Cross organization, supported by deceptions such as soldiers wearing false uniform badges, false vehicle ID, false loading manifests, and false radio traffic. All that & other misidentification were deployed so that any potiental Axis spy might see. The Double Cross messages seem to have been the principle source for the German OB.

I'd recommend a copy of Holts 'The Deceivers'. It is the most complete review of the Allied deception operations, identifiying hundreds of individual operations and how they were linked into a coherent whole. It also has some info on which operations were more or less sucessfull.

[Carl Schwamberger]

'Operation Fortitude' by Joshua Levine has some about organizing the false Allied OB, on both sides of the Channel. Tho I thought the details were a bit haphazard & the connection between the Allied deception efforts & the German intelligence gathering not very clear.

I'd avoid Browns 'Bodyguard of Lies' as it is very dated (1970s) and depended a bit to much on people claiming to be eyewitnesses. Good book for its time, but not much use now as a refrence.

As usual there is some info and references in one of more threads on AHF. I'll try to remember where.

[paspartoo]

There was a statement in a post war interrogation by a German official that they had identified all the American units but not the British ones ( or vice versa). That's what i'm trying to check.

[Carl Schwamberger]

I'll make a little time tomorrow after noon to finish checking my books for that specific item. It seems a odd statement since the deception organization was tossing out a coherent false OB of both Commonwealth and US units. I recall the false Army posted in Scotland for the Norway invasion deception had a mixed composition of US and Commonwealth divisions & Corps HQ. the FUSAG organization was a mixed bag of British and US divisions & corps HQ as well.

Do you recall the officers name? I'll watch for it in the text.

[paspartoo]

I don't think you'll find anything. The TICOM report that says that is I-113 'Interrogation of Major Dr. Rudolf Hentze, Head of Gruppe IV (Cryptanalysis) General der Nachrichtenaufklaerung'

[Carl Schwamberger]

Holt (The Decivers) has two passages relating to this. He draws from Allied post war intelligence reviews of German documents and interrogation of the German officers in the 'Enemy Forces West' section. First Holt claims the head of Enemy Froces West was relying almost entirely on information from the Abwehr agents in the UK, Spain, and perhaps Ireland. He goes on to describe how the OB thus collected did not seem to have been subjected to any critical analysis.

Second the Allied review of the signals intelligence effort aimed at the UK also found it lacked any indepth analysis. The intercepted massages were present enmass and included a larger portion of both actual Allied ground forces message traffic from the British Isles, and the false traffic. A fair portion of the messages were decoded, at least as far as the Germans had penetrated the systems below Typex & SIGABA. However little had been done for sorting through all this to seek out the important details. From this I have the impression to technicians and junior staff were doing their part, but the senior staff were not. Holt does not go into any depth on this, does not name any names, quote anyone, or reproduce passages from any reports. So, we have to assume all this reflects Holts take on it and may diverge from the actual Allied reports.

If Holt is accurate then this statement of Major Dr. Rudolf Hentze, Head of Gruppe IV (Cryptanalysis) General der Nachrichtenaufklaerung' would fit the incomplete analysis of the Allied radio traffic.

Thats about all I can offer off my shelves. If you have any questions about Holts description I'll try to pick out the answers from his text.

[paspartoo]

Thanks for checking. I don't think the version given by British authors is correct. The fact that the whole sigint part of Germany's effort was not released until very recently led people to make generalizations without knowing all the facts.