After Germany invaded Poland in September 1939, the SS converted Auschwitz I, a former WW1 army barracks, into a prisoner-of-war camp, and for the first two years the majority of detainees were Poles. Prisoners were beaten, tortured, and executed for the most trivial of reasons. The first gassings—of Soviet and Polish prisoners—took place in block 11 of Auschwitz I around August 1941.
Construction of Auschwitz II began the following month, and from 1942 until late 1944 freight trains delivered Jews from all over German-occupied Europe to its work camps and gas chambers. Of the 1.3 million people sent to Auschwitz, 1.1 million were murdered. The number of victims includes 960,000 Jews (865,000 of whom were gassed on arrival), 74,000 non-Jewish Poles, 21,000 Romany, 15,000 Soviet prisoners of war, and up to 15,000 others. Those not gassed were murdered via starvation, exhaustion, disease, individual executions, or beatings. Others were killed during medical experiments.
At least 802 prisoners tried to escape, 144 successfully, and on 7 October 1944, two Sonderkommando units, consisting of prisoners who operated the gas chambers, launched an unsuccessful uprising. After the Holocaust ended, only 789 SS personnel (no more than 15 percent) ever stood trial. Several were executed, including camp commandant Rudolf Hess
Birkenau – both the barracks and the roads – was built by the prisoners from Auschwitz.
Detainees arrived packed into cattle carts. Women arrived there in March 1942. If you can imagine – there were 700 in each barracks with five to a pallet and three rows – to include the floor. It was freezing cold in the winter and hot in the summer.
There were 23 main concentration camps, of which most had a system of satellite camps. Including the satellite camps, the total number of Nazi concentration camps that existed at one point in time is at least a thousand, although these did not all exist at the same time