The Holocaust was a genocide carried out by Nazi Germany against European Jews during World War II. The Nazis believed Jews were inferior and began systematically murdering around 4 million Jews. Jews were sent to concentration camps where they were starved, forced to work, and killed. Non-Jews such as Roma, Slavs, homosexuals and disabled people were also targeted and hundreds of thousands were murdered. One of the worst single massacres occurred on November 3, 1943 at Majdanek concentration camp in Poland, where approximately 18,000 Jewish prisoners were killed. The Holocaust finally ended when Nazi Germany surrendered to Allied forces in May 1945.