Many of those not killed in the gas chambers died of starvation, forced labor, infectious diseases, individual executions, and medical experiments.
In the course of the war, the camp was staffed by 7,000 members of the German Schutzstaffel (SS), approximately 12 percent of whom were later convicted of war crimes.
Some, including camp commandant Rudolf Höss, were executed.
The Allied Powers did not act on early reports of atrocities at the camp, and their failure to bomb the camp or its railways remains controversial.
Around 90 percent of those were Jews; approximately one in six Jews killed in the Holocaust died at the camp.