Crimes against the Polish nation committed by Nazi Germany and Axis collaborationist forces during the invasion of Poland, along with auxiliary battalions during the subsequent occupation of Poland in World War II, included the genocide of millions of Polish people, especially the systematic extermination of Jewish Poles. These mass killings were enacted by the Nazis with further plans that were justified by their racial theories, which regarded Poles and other Slavs, and especially Jews, as racially inferior Untermenschen.
By 1942, the Nazis were implementing their plan to murder every Jew in German-occupied Europe, and had also developed plans to reduce the Polish people through mass murder, ethnic cleansing, enslavement and extermination through labor, and assimilation into German identity of a small minority of Poles deemed "racially valuable". During World War II, the Germans not only murdered millions of Poles, but ethnically cleansed millions more through forced deportation to make room for German settlers (see Generalplan Ost and Lebensraum). These actions claimed the lives of 2.7 to 3 million Polish Jews and 1.8 to 2.77 million ethnic Poles, according to Poland's Institute of National Remembrance. German occupation policies in Poland have been recognized in Europe as a genocide, characterized by extremely large death tolls compared to Nazi atrocities in Western European states.