Auschwitz, which is near the Polish city of Oświęcim, was the Nazi regime’s largest camp complex. It consisted of three main camps and about forty secondary camps. The main camp (Auschwitz I) was set up shortly after the German invasion of Poland as a concentration and labor camp primarily for political opponents and prisoners of war. Himmler decided to use Auschwitz for the systematic murder of enemies of the race as well. The first gassings of Jews took place in a special death camp, “Auschwitz II-Birkenau.” It is estimated that by the end of 1944 more than a million people had died in its six gas chambers. The Auschwitz III-Monowitz camp, built in 1942, served especially as a labor camp for various industrial operations, such as I.G. Farben’s “Buna Works,” a plant for producing synthetic rubber.