The persecution of Jews reached its most destructive form in the policies of Nazi Germany, which made the destruction of Jews a priority, culminating in the killing of approximately 6,000,000 Jews during the Holocaust from 1941 to 1945. Originally, the Nazis used death squads, the Einsatzgruppen, to conduct massive open-air killings of Jews who lived in the territories which they had conquered. By 1942, the Nazi leadership decided to implement the Final Solution, the genocide of the Jews of Europe, and increase the pace of the Holocaust by establishing extermination camps for the specific purpose of killing Jews as well as other undesirables such as people who openly opposed Hitler.