The Holocaust ended on May 8, 1945 when Allied powers ended the Nazi Regime. The Holocaust began 12 years earlier when Adolf Hitler came to power in Germany.
What began as a boycott of Jewish businesses escalated to victims being rounded up and sent to either concentration camps or death camps. An estimated 11 million people were killed during this period, including 6 million Jews, which amounted to roughly two-thirds of those who were living in Europe at the time of World War II. Other groups that were targeted during the Holocaust included the disabled, Gypsies, homosexuals and Jehovah's Witnesses, according to About.com.