Using gas vans, Chełmno had its roots in the Aktion T4 euthanasia program. Majdanek began as a POW camp, but in August 1942 it had gas chambers installed. A few other camps are occasionally named as extermination camps, but there is no scholarly agreement on the additional camps; commonly mentioned are Mauthausen in Austria and Stutthof. There may also have been plans for camps at Mogilev and Lvov.
After 1945 the name was applied to the displaced persons camp established nearby, but it is most commonly associated with the concentration camp. From 1941 to 1945, almost 20,000 Soviet prisoners of war and a further 50,000 inmates died there. Overcrowding, lack of food and poor sanitary conditions caused outbreaks of typhus, tuberculosis, typhoid fever and dysentery, leading to the deaths of more than 35,000 people in the first few months of 1945, shortly before and after the liberation.