Operation Tannenberg

Operation Tannenberg
Unternehmen Tannenberg
Part of Generalplan Ost
The mass murder of Polish townsmen in Reichsgau Wartheland (western Poland) during Operation Tannenberg on 20 October 1939.
LocationGerman-occupied Poland
DateSeptember 1939 – January 1940
TargetPoles
Attack type
Mass shooting, summary execution, genocidal massacres
WeaponsFirearms
Gas vans
Deaths20,000 deaths (during 1–2 months) in 760 mass executions by SS Einsatzgruppen
Perpetrators Nazi Germany, specifically the Einsatzgruppen
MotiveAnti-Polish sentiment, Nazi racism, destruction of the Polish Intelligentsia

Operation Tannenberg (German: Unternehmen Tannenberg, Polish: Operacja Tannenberg) was one of the first anti-Polish extermination actions by Nazi Germany in German-occupied Poland from September 1939 to January 1940. The operation was conducted with the use of the Sonderfahndungsbuch Polen, a proscription list of more than 61,000 members of the Second Polish Republic's elite were to be arrested then interned or shot.

Around 20,000 Poles were arrested and killed by the Einsatzgruppen in a number of mass killings during Operation Tannenberg, which was followed by the shooting and gassing of hospital patients and disabled adults as part of the wider Aktion T4 programme.