Operation Tannenberg (German: Unternehmen Tannenberg) was the codename for one of the extermination actions directed at the Polish people during World War II, part of the Generalplan Ost. Conscription lists (Sonderfahndungsbuch Polen), prepared by Germans before the war, identified more than 61,000 members of the Polish elite: activists, intelligentsia, scholars, actors, former officers, and others, who were to be interned or shot. Members of the German minority living in Poland assisted in preparing the lists.
The plan was created in May 1939. Following the orders of Adolf Hitler, a special unit dubbed Tannenberg was created within the Reich Main Security Office (Reichssicherheitshauptamt). It commanded a number of Einsatzgruppen der Sicherheitspolizei und des SD formed with Gestapo, Kripo and SD officers who were theoretically subordinate to local Wehrmacht commanders. Their task was to arrest all the people listed on the proscription lists prepared before the outbreak of World War II.
First, in August 1939 about 2,000 activists of Polish minority organisations in Germany were arrested and murdered. The second part of the action began on September 1, 1939, and ended in October, resulting in at least 20,000 deaths in 760 mass executions by Einsatzgruppen special task units with some help from regular Wehrmacht (armed forces) units. In addition, a special formation was created from the German minority living in Poland called Selbstschutz, whose members had trained in Germany before the war in diversion and guerilla fighting (see: Deutscher Volksverband, the German People's Union in Poland). The formation was responsible for many massacres and due to its bad reputation was dissolved by Nazi authorities after the September Campaign.
See also 
- Pacification operations in German-occupied Poland
- History of Poland (1939–1945)
- Wawelberg Group
- Operation Himmler
- Various authors (2000). Monografia obozu KL Stutthof. Państwowe Muzeum Stutthof w Sztutowie.[dead link]
- Andrzej Leszek Szcześniak (2001). Plan zagłady Słowian - Generalplan OST. Radom, POLWEN. ISBN 83-88822-03-9.
- Alfred Spiess, Heiner Lichtenstein: Unternehmen Tannenberg. Der Anlass zum Zweiten Weltkrieg. Korrigierte und erweiterte Ausgabe. (Ullstein-Buch ; Nr. 33118 : Zeitgeschichte) Ullstein, Frankfurt/M ; Berlin 1989, ISBN 3-548-33118-1.
- (English) Verbatim transcript of Part I of the book The German New Order in Poland published for the Polish Ministry of Information by Hutchinson & Co., London, in late 1941. The period covered by the book is September, 1939 to June, 1941
- (French) La Station de Radiodiffusion de Gleiwitz (Gliwice) - L'Opération TANNENBERG
- (German) Unternehmen Tannenberg - August 1939: Wie der SD den Überfall auf Polen vorbereitete (III) bei wissen.spiegel.de PDF