The holocaust was the organized, routine annihilation of six million Jews by the Nazi regime and their collaborators as a central act of state during World War II. In 1933 approximately nine million Jews lived in the 21 countries of Europe that would be occupied by Germany during the war. By 1945 two out of every three European Jews were the primary victims, hundreds of thousands of Roma (Gypsies) and at least two hundred fifty thousand mentally of physically disabled persons were also victims of the Nazi genocide. As Nazi cruelty spread across Europe from 1933 to 1945, millions of other innocent people were persecuted and murdered. More than three million Soviet prisoners of war were killed because of their nationality. Slaves were targeted for slave labor, and as result, almost two million literally worked their selves to death. Homosexuals and others considered "anti social" were also persecuted and often murdered. In addition, thousands of political and religious protesters such as a communist, socialists, trade unionists, and Jehovah's Witness were persecuted for their beliefs and behaviors and many of these individuals died because of abuse. The concentration camp is most closely associated with the Holocaust and remains a lasting symbol of the Nazi regime. The first camps opened after the Nazis took power in January 1933; they continued as a basic part of Nazi rule until May 8, 1945 when the war, and the Nazi regime, ended.
The events of the Holocaust occurred in two phases: 1933-1939 and 1939-1945.
Immediately on coming to power in 1933, Adolph Hitler's Law began to deprive German Jews regularly of all their rights of citizenship. Their rights were finally taken away; in 1935 by the Nuremberg Laws. At the same time a brutal, crude, Anti-Semitism drove more than two hundred and fifty thousand Jews, into exile. In every town and village, public slogans declared: "The Jew is our misfortune", " Jews not wanted here".