The Holocaust was a genocide carried out by Nazi Germany against European Jews between 1933-1945. An estimated 6 million Jews were murdered, along with 5 million others including Roma, Slavs, homosexuals and political opponents. Jews were systematically persecuted through legislation and violence, culminating in extermination camps where most were gassed. While resistance occurred, most victims were unable to escape the well-organized Nazi killing machine before Allied liberation in 1945.