The Holocaust: In occupied Poland, the Nazis close off the Warsaw Ghetto from the outside world.

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.

Nazism, formally named National Socialism, is the far-right totalitarian socio-political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Germany. During Hitler's rise to power, it was frequently referred to as Hitler Fascism and Hitlerism. The term "neo-Nazism" is applied to other far-right groups with similar ideology, which formed after World War II, and after Nazi Germany collapsed.

The Warsaw Ghetto was the largest of the Nazi ghettos during World War II and the Holocaust. It was established in November 1940 by the German authorities within the new General Government territory of occupied Poland. At its height, as many as 460,000 Jews were imprisoned there, in an area of 3.4 km² (1.3 sq mi), with an average of 9.2 persons per room, barely subsisting on meager food rations. Jews were deported from the Warsaw Ghetto to Nazi concentration camps and mass-killing centers. In the summer of 1942, at least 254,000 ghetto residents were sent to the Treblinka extermination camp during Großaktion Warschau under the guise of "resettlement in the East" over the course of the summer. The ghetto was demolished by the Germans in May 1943 after the Warsaw Ghetto Uprising had temporarily halted the deportations. The total death toll among the prisoners of the ghetto is estimated to be at least 300,000 killed by bullet or gas, combined with 92,000 victims of starvation and related diseases, the Warsaw Ghetto Uprising, and the casualties of the final destruction of the ghetto.