The Holocaust: Karl Fritzsch, deputy camp commandant of the Auschwitz concentration camp, experiments with the use of Zyklon B in the gassing of Soviet POWs.

The Holocaust, known in Hebrew as the Shoah, was the genocide of European Jews during World War II. From 1941 to 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europe, around two-thirds of Europe's Jewish population. The murders were committed primarily through mass shootings across Eastern Europe and poison gas chambers in extermination camps, chiefly Auschwitz-Birkenau, Treblinka, Belzec, Sobibor, and Chełmno in occupied Poland. Separate Nazi persecutions killed millions of other non-Jewish civilians and prisoners of war (POWs); the term Holocaust is sometimes used to include the murder and persecution of non-Jewish groups.

Karl Fritzsch was a German SS official who served as deputy and acting commandant at the Auschwitz concentration camp from 1940 to 1941. He is best known as the official responsible for the death of priest Maximilian Kolbe and, according to Rudolf Höss, first suggesting using poisonous gas Zyklon B and experimenting with gas chambers for the purpose of mass murder at Auschwitz. Fritzsch served at a number of Nazi concentration camps until 1944 when he was implicated in a corruption scandal and dismissed from his positions. Fritzsch was sent to front line duty and is believed to have died at the Battle of Berlin on 2 May 1945, but this is unconfirmed, and his fate is unknown.

Auschwitz, also known as Oświęcim, was a complex of over 40 concentration and extermination camps operated by Nazi Germany in occupied Poland during World War II and the Holocaust. It consisted of Auschwitz I, the main camp (Stammlager) in Oświęcim; Auschwitz II-Birkenau, a concentration and extermination camp with gas chambers, Auschwitz III-Monowitz, a labour camp for the chemical conglomerate IG Farben, and dozens of subcamps. The camps became a major site of the Nazis' Final Solution to the Jewish question.