Operation Himmler, also called Operation Konserve, consisted of a group of 1939 false-flag undertakings planned by Nazi Germany to give the appearance of Polish aggression against Germany. The Germans then used propaganda reports of the events to justify their invasion of Poland, which started on 1 September 1939. Operation Himmler included the Germans staging false attacks on themselves - directed at innocent people or at concentration-camp prisoners. The operation arguably became the first act of the Second World War in Europe.