Content Warning: This section of the guide includes discussion of antisemitism, genocide, and the violence of war.

The main events in The Keeper of Hidden Books take place in Warsaw from 1939 to 1945 and describe the Nazi occupation of the city. The Warsaw ghetto is also a significant setting in the novel. Historically, the Warsaw ghetto was the largest of the Nazi ghettos established during World War II, with upwards of 400,000 Jews forced to live inside its walls. Many of these people were not originally residents of Warsaw; they were forced into the city as they escaped fighting in other places. In November of 1940, the Nazis closed the ghetto off from the rest of the city and surrounded the 1.3 square mile area with a 10-foot-high fence topped with barbed wire. It is estimated that food rations amounted to 180 calories per person per day, and due to the close living quarters and the starvation conditions, thousands of people died of hunger and disease inside the ghetto.

In the summer of 1942, the Nazis began a campaign of deportation from the Warsaw ghetto. Large numbers of the ghetto’s residents were rounded up and forced onto trains bound for Treblinka, an extermination camp.