Adolf Hitler believed that the Polish elites might inspire the Poles to disobey their new German masters so he decreed that they had to be eliminated beforehand . The aim was the elimination of Polish society 's elite , which was very broadly defined as : Polish nobles , intelligentsia , teachers , entrepreneurs , social workers , military veterans , members of national organizations , priests , judges , political activists , and anyone who had attended secondary school . It was continued by the German AB-Aktion operation in Poland in the spring and summer of 1940 , which saw the massacre of Lwów professors and the execution of about 1,700 Poles in the Palmiry forest . Several thousand civilians were executed or imprisoned . The '' Einsatzgruppen '' were also responsible for the indiscriminate killing of Poles during the 1941 German invasion of the Soviet Union ( which itself had invaded a sizeable portion of pre-WWII Polish territory , killing dozens of thousands of imprisoned Poles in turn ) . Our strength is our quickness and our brutality ... . I have given the order — and will have everyone shot who utters but one word of criticism — that the aim of this war does not consist in reaching certain geographical lines , but in the enemies ’ physical elimination . Thus , for the time being only in the east , I put ready my Death ’s Head units , with the order to kill without pity or mercy all men , women , and children of the Polish race or language ... Adolf Hitler , Obersalzberg Speech , given on 22 August 1939 , a week before the invasion The massacres of Poles in Volhynia and Eastern Galicia were part of an ethnic cleansing operation carried out by the Ukrainian Insurgent Army ( UPA ) West in the Nazi-occupied regions of Eastern Galicia ( Nazi created Distrikt Galizien in General Government ) , and UPA North in Volhynia ( in Nazi created Reichskommissariat Ukraine ) , from March 1943 until the end of 1944 . The peak took place in July/August 1943 when a senior UPA commander , Dmytro Klyachkivsky , ordered the liquidation of the entire male Polish population between 16 and 60 years of age . Despite this , most were women and children . The UPA killed 40,000 – 60,000 Polish civilians in Volhynia , from 25,000 to 30,000 – 40,000 in Eastern Galicia . The killings were directly linked with the policies of the Bandera fraction of the Organization of Ukrainian Nationalists , whose goal , specified at the Second Conference of the OUN-B , was to remove non-Ukrainians from a future Ukrainian state
dozens of thousands of imprisoned Poles
Katyn massacre
Genocides in history