Germany first used concentration camps as places of unlawful incarceration of political opponents and other " enemies of the state " . Large numbers of Jews were not sent there until after '' Kristallnacht '' in November 1938 . Although death rates were high , the camps were not designed as killing centers . After war broke out in 1939 , new camps were established , some outside Germany in occupied Europe . In January 1945 , the SS reports had over 700,000 prisoners in their control , of which close to half had died by the end of May 1945 , according to most historians . Most wartime prisoners of the camps were not Germans but belonged to countries under German occupation . After 1942 , the economic functions of the camps , previously secondary to their penal and terror functions , came to the fore . Forced labor of camp prisoners became commonplace . The guards became much more brutal , and the death rate increased as the guards not only beat and starved prisoners , but killed them more frequently . '' Vernichtung durch Arbeit '' ( " extermination through labor " ) was a policy — camp inmates would literally be worked to death , or to physical exhaustion , at which point they would be gassed or shot . The Germans estimated the average prisoner 's lifespan in a concentration camp at three months , due to lack of food and clothing , constant epidemics , and frequent punishments for the most minor transgressions . The shifts were long and often involved exposure to dangerous materials
Kristallnacht
Kristallnacht
The Holocaust