The Holocaust was the murder of six million Jews and millions of others by the Nazis and their collaborators during World War II. Mass killings began in June 1941 with the shooting of Jewish civilians during the German invasion of the Soviet Union. At the end of 1941, the Germans began deporting Jews to killing centers in occupied Poland. By May 1945, about two out of every three Jews in Europe had been murdered.
US Holocaust Memorial Museum
Prewar European Jewish population: 9.5 million.
Before World War II, more than half of the world's Jewish population lived in Europe. Most Jews lived in eastern Europe, primarily in the Soviet Union and Poland.
The Nazi party came to power in Germany in 1933. The Germans moved to extend their power in central Europe, annexing Austria and destroying Czechoslovakia.
Germany invaded Poland in 1939, beginning World War II. Over the next two years, German forces conquered most of Europe. The Germans established ghettos in occupied eastern territories, isolating and persecuting the Jewish population.
Nazi anti-Jewish policy expanded with the invasion of the Soviet Union in 1941. Mobile killing units murdered Jews, Roma (also called Gypsies), Soviet political commissars, and others.
The Germans and their collaborators deported Jews to killing centers in occupied Poland. At the largest killing center, Auschwitz-Birkenau, transports arrived almost daily from across Europe.
By war's end, almost six million Jews and millions of others had perished in the Holocaust.
Postwar Jewish Population, ca. 1950: 3.5 million