At the time of the Second World War, IG Farben was the largest chemical manufacturing company in Europe and the fourth largest commercial interest in the world having successfully conglomerated itself from various smaller companies in 1925. These companies included Bayer, most famous for being the creator and rights holder for aspirin, the world's most successful drug. BASF, one of the first companies to successfully synthesise ammonia for fertilisers and AGFA, the inventor of x-ray plates. It was so large that a conspiracy was unveiled during the war in which it was found to be manipulating oil prices in collusion with US Standard Oil in a conspiracy dubbed by the US courts as the 'Farben Cartel.'
IG Farben itself became infamous for first cooperating with the Nazis and then for taking advantage of slave labour offered by the concentration camps and the invention, dissemination and profiting from the manufacture of Zyklon B used in the 'Shoah by Gas.'
During the Nazi's initial sweep across Eastern Europe after the beginning of Barbarossa in June 1941, the management of IG Farben directed the Wehrmacht as to which facilities should be seized for use by the company. The company's interest in an area near Aushcwitz in Poland was peaked because of the strong rail links in the area and the Nazi's interest in setting up a concentration camp for Eastern European Jews near the town: Heinrich Himmler had promoted the idea of using labour from the concentration camp to power the factory in an effort to Germanise the region and attract German settlers to a new commercial centre.
Due to the surprisingly large demands of IG Farben on slave labour for their new facility (the complex can still be seen here on Google Maps) Himmler had to triple the size of the camp from 10,000 prisoners while IG Farben agreed to pay the treasury 4 Reichsmark a day for each labourer. The SS was charged with selecting the most violent prisoners - named kapos - to act as slave-drivers, beating the Jewish slaves to make them work harder.
The facility - named Buna-Werke - was constructed by 10,000 Red Army prisoners in the summer of 1941 after they were marched miles from the front without food or sleep. At the site, they were not fed, but were told to 'graze' for what they could find in local fields.
IG Farben's Buna Werke, though the directors denied all knowledge, was the site for the deaths of 83,000 workers from the Eastern front and Morowitz (Auschwitz III) yet produced no chemical products at all before IG Farben's dissolution. The company also funded the human experimentation of Dr Mengele and Dr Vetter at Auschwitz-Birkenau who managed to barter down the price per human subject from 200 Reichsmark to 170. Vetter wrote: 'I feel like I'm in paradise!'
IG Farben also held the patent for Zyklon B and a 42% stake in the company that manufactured it.
At the Nuremburg Trials held by the allies for war crimes, 24 directors and managers of IG Farben were indicted. 13 received prison sentences of between one and eight years.
Hermann Schmitz, the company director spent four years in prison and then went on to join the supervisory board of Deutsche Bank and became honorary president of Rheinische Stahlwerke AG. George von Schnitzler was the prime intermediary between the SS and Nazi leaders and IG Farben, he picked out and planned sites, including Buna-Werke. He served one year in prison before taking a position as president of Deutsch-Ibero-Amerikanische Gesellschaft and appearing in high society magazines. Fritz ter Meer served two years for slavery and spoliation then took positions on several boards including Bayer AG, a former IG Farben subsidiary. Otto Ambros served two years and became an adviser to Dow Chemical. Heinrich Bütefisch served two years and became a director for Deutsche Gasolline. Max Ilgner served five years and was the appointed chairman of Zug. Heinrich Oster served one years and joined the supervisory board of Gelsenberg AG. All of the 24 had resumed positions in business and high society by the mid-fifties in time for the 'German Eocnomic Miracle.'