The German ‘ultra’: signals intelligence in Yugoslavia 1943–1944

ABSTRACT

This article deals with the extensive signals surveillance program operated by the Wehrmacht and directed at their most dangerous enemy in the Balkans, the Yugoslav Partisans. This subject has so far received surprisingly little attention in academic circles despite the fact that it was one of the crucial pillars of the entire Axis counter-insurgency effort in Yugoslavia and that it was one of the most successful actions of its kind conducted by the German intelligence. Based largely osn previously unpublished primary sources, as well as post-war literature, this article will outline the workings of the program during its heyday in the years 1943–1944 and seek to establish its impact on the battlefield. As such, it will hopefully prove to be useful to both students of wartime events in the Western Balkans and to researchers of intelligence services during the Second World War in general.

KEYWORDS:

• Yugoslavia
• Second World War
• Wehrmacht
• Partisans
• signals intelligence
• SIGINT
• radio surveillance

Notes

¹ Unless otherwise stated, all general information on the war in Yugoslavia presented in the introductory chapter comes from the two classic works in non-Slavic languages, namely Klaus Schmider’s Partisanenkrieg in Jugoslawien 1941–1944 (Hamburg: E. S. Mittler & Sohn, 2002); and Jozo Tomasevich’s War and Revolution in Yugoslavia, 1941–1945: Occupation and Collaboration (Stanford, CA: Stanford University Press, 2001).

² In addition to the German contingent, the Italian 2nd Army with more than 10 divisions had been deployed in the southern NDH and Montenegro from April 1941 to September 1943.

³ At this time, the armed wing of the Communist-led People’s Liberation Movement (Narodnooslobodilački pokret, NOP) was rechristened People’s Liberation Army and Partisan Detachments of Yugoslavia (Narodnooslobodilačka vojska i partizanski odredi Jugoslavije, NOVJ): Gaj Trifković, ‘A Case of Failed Counter-Insurgency: Anti-Partisan Operations in Yugoslavia 1943,’ The Journal of Slavic Military Studies, 24, no. 2 (2015), 315–6; and Fabijan Trgo, ‘4. i 5. neprijateljska ofanziva: zimske i proljetne operacije u Jugoslaviji 1943,’ in Neretva – Sutjeska 1943: Zbornik radova naučnog skupa ‘Neretva – Sutjeska 1943’ održanog od 27.6. do 2.7.1968 god. u Sarajevu, ed. Branko Borojević (Belgrade: VII, 1969), 24.

⁴ Schmider, Partisanenkrieg, 442–3; Nemačka obaveštajna služba u Jugoslaviji, vol. IV (Belgrade: SSUP, 1959), 199–209; and United States National Archives and Records Administration, Washington, DC; Record Group 242, Microfilm series T-501, roll 248, frame 556, Commanding General in Serbia [CGIS], Intelligence summary (August 28, 1942) [hereinafter: NARA/microfilm series/roll/frame (if available)]. The monitoring of Chetnik communications by the Germans would easily warrant an article of its own and will therefore not be expounded upon any further. In short, the Chetnik traffic – including the high-grade messages exchanged between Mihailović and the Yugoslav government-in-exile – continued to be successfully read until the end of the war. The task was made easier by the fact that the enciphering method (double transposition) remained largely the same throughout this period. In 1944, German SIGINT units in the Balkans deciphered some 12,400 Chetnik messages: NARA, Record Group 457, Entry 9032, Box22, KONA 4, Deciphering reports I–IV/1944 [hereinafter: KONA 4-year, volume/page; I would like to thank Mr. Miloš Bojanić for providing me with copies of these reports].

⁵ Mirko Ćetković, Veze u NOB-u 1941–1942, vol. I (Belgrade: VIZ, 1976), 314–6, 322; Veseljko Huljić and Milovan Dželebdžić, Veze u NOB-u 1943–1945, vol. II (Belgrade: VIZ, 1984), 13–14; NARA/T-315/2258/1258, CGIS, Communist insurgency in former Yugoslavia (October 31, 1942); Schmider, Partisanenkrieg, 281, 442; and NARA/T-314/560/798, 823, 7th SS Mountain Division [MD], After-action reports, Operation Schwarz (July 25, 1943).

⁶ Schmider, Partisanenkrieg, 288–316.

⁷ Oslobodilački rat naroda Jugoslavije, vol. I (Belgrade: Vojnoizdavački zavod, 1957), 633; NARA/T-313/196/7449018, OBSO, Situation appreciation (November 1, 1943); and see also Huljić and Dželebdžić, Veze, diagrams nos. 16, 20, 27, 38.

⁸ NARA/T-313/196/7457599, 7457611, 7457625-6, 7457634, PzAOK 2/Signals, War diary (September 11, October 6, November 16, and December 12, 1943); Georg Tessin, Verbände und Truppen der deutschen Wehrmacht und der Waffen-SS im Zweiten Weltkrieg 1939–1945, vol. II (Osnabrück: Biblio Verlag, 1978), 121; and KONA 4-1943, IV/2; CSDIC [Combined Services Detailed Interrogation Centre]/CMF/Y36, Statement of Hermann Reudelsdorff (May 17, 1945), 3.

⁹ NARA/T-311/286, KONA 4, Order No. 3 (March 2, 1944); NARA/T-311/196/510-511, Deployment KONA 4 (December 17, 1944); and see also personnel and task overview on p. 2 in each one of the already cited KONA 4’s three-monthly reports from 1944.

¹⁰ NARA/T-313/196/7457626, PzAOK 2/Signals, War diary (November 16, 1943); ibid., 7456841-2, PzAOK 2, Supplement to daily intelligence report [SDIR] (December 15, 1943); and NARA/T-313/488/127, PzAOK 2 to V SS Mountain Corps [MC] (December 21, 1943).

¹¹ KONA 4-1944, I/11, II/4, III/5, IV/7; German foreign ministry’s political archive, TICOM collection, box 143, Gruppe Nachrichtenaufklärung, Activity report March 1944, 2–3 [hereinafter GFMPA/TICOM/143/GNA-year, volume/page]; CSDIC/SIR1704, Appendix 7 to statement of NCO Herzfeld (July 8, 1945), 1; European Axis Signals Intelligence in World War II as Revealed by TICOM Investigations and by Other Prisoner of War Interrogations and Captured Material, Principally German, vol. IV (Washington, DC: Army Security Agency, 1946), 173–4; and for a detailed description of NOVJ ciphers, see TICOM reports I-52 (5–9) and I-69 (1–22, 30) pertaining to the interrogation of Heinz Wolfgang Herzfeld of In 7/VI (August 12 and September 22, 1945, respectively). Target Intelligence Committee, or TICOM, was a U.S. program devised to seize German intelligence assets. For more on its findings and related documents, see http://chris-intel-corner.blogspot.co.at and http://www.ticomarchive.com (last accessed June 8, 2017).

¹² See the following chapters in Veze u NOB-u 1941–1945: ratna sećanja (Belgrade: VIZ, 1981): Refik Piskavica, ‘Bio sam slušalac prvog šifrantskog kursa pri Vrhovnom štabu,’ vol. IV, p. 148; Branka Savić, ‘Rad šifranata u VŠ, veze VŠ u teškim bitkama i organizacija šifrantske službe,’ vol. V, pp. 221–2; Nikola Turčinov, ‚Bio sam šifrant u Rečnoj ratnoj floti’ (ibid., 252); and Višnja Habunek-Lozica,‘Šifrant u GŠ Hrvatske’ (ibid., 369–70).

¹³ GFMPA/TICOM/143/GNA-1944, VIII/2, X/6; NARA/T-311/194/457, OBSO, Note for war diary (October 15, 1944); and KONA 4-1944, IV/6.

¹⁴ NARA/T-311/286, KONA 4, Order No. 3 (March 2, 1944); NARA/T-314/563/1033, XV MC to 264th Infantry Division [ID] (January 22, 1944); and NARA/T-311/189/1000, 1028, KONA 4, Intelligence summaries (October 14 and 19, 1944).

¹⁵ See the following chapters in Sećanja: Nebojša Pupić, ‘Saveti Veljka Dragičevića,’ vol. IV, p. 157; Levi Moric, ‘Moja sećanja na veze u ratu’ (ibid., 202); Ivan Bolf, ‘Sa radiotelegrafskog kursa na dužnost u korpusnu oblast 10. korpusa’ (ibid., 253–6); Branislav Gvozdić, ‘Šifrantska služba u 10. diviziji 5. udarnog korpusa 1944–1945,’ vol. V, p. 276; Haših Kajtazović, ‘Časno je biti šifrant’ (ibid., 385); and CSDIC/SIR 1704, Statement of NCO Herzfeld (July 8, 1945), 12.

¹⁶ Louis Mahrer, Bora – Erzählung. Mit einem historischen Kommentar von Robert Streibel (Weitra: Verlag Bibliothek der Provinz, 2016).

¹⁷ Zbornik dokumenata i podataka o Narodno-oslobodilačkom ratu naroda Jugoslavije, vol. II, part 13 (Belgrade: VII, 1949–86), 102, 156, SHQ to 3rd NOVJC (May 14 and 20, 1944) [hereinafter: Zbornik/volume/part/page]; Zbornik/II/14/57, SHQ to all subordinated commands (September 6, 1944); Zbornik/IV/26/436-437, 1st NOVJC, Radio log (June 5, 1944); Mihajlo Marić, ‘Fragmenti iz okupiranog Beograda,’ in Veze u NOB-u 1941–1945: ratna sećanja (Belgrade: VIZ, 1981); and NARA/T-311/188/985-6, OBSO/Secret Field Police, Activity report for August 1944 (September 15, 1944).

¹⁸ Compare KONA 4 intelligence summaries from the first half of January 1945 (NARA/T-501/266/494-579), OBSO/HGE DIRs from March 1945 (e.g. NARA/T-78/476/6458759, 6458778, 6458800, 6458840; in departure from the usual practice, the intercepts are denoted as ‘Ignaz-Meldung,’ ‘Artur-Meldung,’ etc.), and the meagre results produced by OKH (GFMPA/TICOM/143/GNA-1945, I/5, II/3, III/6).

¹⁹ NARA/T-313/196/7457061, 7457088-9, PzAOK2, SDIRs (October 13 and 21, 1943); Zbornik/II/10/397-398, Tito to 2nd NOVJC (October 21, 1943); and NARA/T-313/189/7449063-6, PzAOK2, Conference on ‘Kugelblitz’ (November 19, 1943).

²⁰ Milutin Morača, Ratni dnvenik (Belgrade: VIZ, 1982), 154–5 [diary entry for] (December 14, 1943); NARA/T-78/331/6287988, OBSO, Daily report [DR] (December 14, 1944); and NARA/T-313/196/7456841-3, PzAOK2, SDIR (December 15, 1943).

²¹ Ahmet Džonlagić, 27. divizija (Belgrade: VIZ, 1983), 88; and NARA/T-313/487/25, 27, OBSO, Evening intelligence reports [EIR] (December 27 and 28, 1943).

²² Morača, Dnevnik, 164–5 (December 28, 1943); and NARA/T-313/487/19, OBSO, EIR (December 29, 1943).

²³ For more on the NOVJ incursions into Serbia in 1944, see Gaj Trifković, ‘The Key to the Balkans: The Battle for Serbia 1944,’ The Journal of Slavic Military Studies, 28, no. 3 (2015), 524–55.

²⁴ NARA/T-78/331/6288678, 6288714, 6288879, OBSO, DR (April 23 and 28, and May 8, 1944); compare also Tito’s cables to NOVJ commands in Eastern Bosnia in Zbornik/II/12/578, 597 (April 21 and 23, 1944), and Zbornik/II/13/22, 27–8 (May 3 and 5, 1944); see also cables sent by the 3rd NOJVC in Zbornik/IV/25/640, 642, 644 (May 3, 6–7, 9, and 11, 1944); Otto Kumm, Vorwärts Prinz Eugen! Die Geschichte der 7. SS-Freiwilligen-Division ‘Prinz Eugen’ (Dresden: Winkelried Verlag, 2007), 172–7; and Oslobodilački, vol. II, 200–3.

²⁵ See OBSO EIRs in NARA/T-311/192/92, 115, 150, 194 (July 21, 22, 24, and 25, 1944), and 598, 642, 683, 877, 922 (August 17, 19, 20, 26, and 27, 1944); Đorđe Orlović, Šesta lička proleterska divizija ‘Nikola Tesla’ (Belgrade: VINC, 1990), 409–10; Dušan D. Samardžija, 11. krajiška NOU divizija (Belgrade: VINC, 1987), 181–6; Miloš Vuksanović, 1. proleterska brigada (Belgrade: ISI, 1981), 350; and Trifković, Serbia, 540–4.

²⁶ NARA/T-313/189/7448774, 7448784, 7448787, PzAOK2, War diary (October 9, 14, and 15, 1943); Zbornik/IV/18/221–222, 10th NOVJD to SHQ (October 16, 1943); and Gligo Mandić, 17. istočnobosanska NOU divizija (Belgrade: VIZ, 1976), 62.

²⁷ Ibid., 109–21; and NARA/T-314/1545/1281-1282, PzAOK 2 to LXIX RC (January 12, 1944).

²⁸ NARA/T-314/561/151, XV MC to 1st CD (January 8, 1944); and NARA/T-314/1544/151 (LXIX RC, War diary December 12, 1943), 638 (LXIX RC to PzAOK 2, December 27, 1943).

²⁹ NARA/T-314/560/1203, 1231, 1239, XV MC, War diary (April 4 and 28, and May 6, 1944). Some Yugoslav authors had erroneously attributed the success of the 392nd ID’s operation to enemy agents and lax security in lower Partisan commands: Petar Kleut, 11. korpus NOVJ (Belgrade: VINC, 1987), 108.

³⁰ NARA/T-314/1630/517, LXXXXI Army Corps [AC], DR (December 13, 1944).

³¹ NARA/T-1022/3956, Admiral of the Adriatic, War diary (January 19–21, 1944); and Kazimir Pribilović, 4. pomorski sector Mornarice NOVJ (Belgrade: VINC, 1988), 200–1.

³² NARA/T-313/196/7456797, PzAOK2, SDIR (December 24, 1943); NARA/T-311/285/742-751, Ln.-Fu.-Ueberw.-Kp.z.b.V.1 to OBSO (November 1, 1943); and Nemačka, vol. IV, 212–5.

³³ NARA/T-311/285/618, Order of OBSO (March 4, 1944); NARA/T-311/179/812-814, HGE, Action Casanova (August 8, 1944); and NARA/T-314/1548/150-153, PzAOK2 to LXIX RC (June 25, 1944). The Partisans saw through the ploy and began applying countermeasures, but this did not remain hidden for long, thanks to SIGINT: ibid., frame 68, LXIX RC, Subject: Casanova (August 3, 1944).

³⁴ Pavle Jakšić, Nad uspomenama, vol. II (Belgrade: Rad, 1990), 579.

³⁵ Zbornik/IV/25/649, 3rd NOVJC to SHQ (May 20, 1944); for the recording of names of Partisan officers, see e.g. NARA/T-311/189/1260-1261, KONA 4 Intelligence summary (November 26, 1944), subparagraphs marked with the Roman numeral ‘II.’

³⁶ NARA/T-313/196/7457139, PzAOK 2, SDIR (September 28, 1943); NARA/T-311/189/293-298, OBSO, Calculation notes on NOVJ strength (end of 1943, July 5 and August 14, 1944); see also KONA 4 intelligence summaries in ibid., 950–1, 1023, 1297 (October 5 and 18, and December 2, 1944), and 1156–7, 1307, KONA 4, Maps (October 31 and December 1, 1944); and NARA/T-311/196/328, KONA 4, Composition chart NOVJ (October 31, 1944).

³⁷ NARA/T-313/196/7456913, 7457011, 7457059, PzAOK 2, SDIRs (October 22, November 3 and 29, 1943); and NARA/T-311/286, PzAOK 2 to OBSO (2.5.1944). For more on Huot’s mission(s), see his book Guns for Tito (New York: L.B. Fischer, 1945).

³⁸ NARA/T-313/196/7456955, 7457032, 7457078, 7457087, PzAOK 2, SDIRs (October 14, 16, and 30, and November 17, 1943); and see also KONA 4 intelligence summaries in NARA/T-311/189/930 (October 3, 1944), 1241–2 (November 17, 1944), and NARA/T-501/266/485 (December 30, 1944). For more on the relationship between the Partisans and the Western Allies, see Gaj Trifković, ‘The Long Way to Trieste: Operations in the Yugoslav Littoral 1944–1945’ (the article will appear in Global War Studies in 2018).

³⁹ NARA/T-313/196/7457176-7, 7456964, 7456881-4, PzAOK 2, SDIRs (September 17, November 15, and December 5, 1944); NARA/T-311/179, KONA 4/Evaluation to HGE (January 13, 1944); and Branko Petranović, Istorija Jugoslavije 1918–1988, vol. II (Belgrade: NOLIT, 1988), 281.

⁴⁰ NARA/T-313/196/7457214, 7457206, 7457196, 7456978, 7456955, PzAOK 2, SDIRs (September 8, 10, and 17, and November 12 and 17, 1943); and NARA/T-313/192/7452306, 7452310, Correspondence OBSO–PzAOK 2 (November 2 and 12, 1943).

⁴¹ NARA/T-313/196/7457078, 7456990-1, 7456861-2, PzAOK 2, SDIRs (October 16, November 5, and December 10, 1943); NARA/T-311/189/603, OBSO/Intelligence, Memorandum (July 12, 1944); Gaj Trifković, ‘Making Deals With the Enemy: Partisan–German Contacts and Prisoner Exchanges in Yugoslavia 1941–1945’ (diss.; Karl-Franzens University Graz, 2013), 225, 269–75, 287; and for an abridged version, see Global War Studies, 10, no. 2 (2013), 6–37.

⁴² For instance, the Partisans detonated no less than 186 charges on the Novska–Slavonski Brod railway line in Croatia on March 27–28, 1944: NARA/T-78/331/6288525, OBSO, DR (March 29, 1944).

⁴³ Schmider, Partisanenkrieg, 587.

⁴⁴ For more on German strategic and operational–tactical considerations, see ibid., 417–20, 535–54.

Additional information

Notes on contributors

Gaj Trifković

Gaj Trifković obtained both his MA and PHD in contemporary and history of South-East Europe from Karl-Franzens University of Graz, Austria, in 2010 and 2013, respectively. His thesis on prisoner exchange in Yugoslavia will be published by Brécourt Academic in 2018. He is also the author of a series of articles on Second World War in Yugoslavia which had been published in the Journal of Slavic Military Studies, Global War Studies, and other relevant peer-reviewed journals. He currently resides in Vienna, Austria.