During the second World War, some people in occupied countries such as France, The Netherlands, and Denmark resisted Nazi forces. These brave men and women met secretly and planned ways to thwart the German army's efforts to round up Europe's Jews and others.
Many of the techniques described in Lowry's book are historically accurate. Denmark in particular was highly successful in protecting its Jewish population, both by transporting Jews out of the country and hiding them in their homes. Sadly, many in the resistance paid for their bravery with their lives, as Peter and Anne Marie's sister do in the story.
The Resistance in Number the Stars refers to a group of courageous men and women who attended secret meetings and passed out a secret newspaper with news specifically important to the Jewish population of Denmark. They were a group who rebelled against the German troops in order to keep the Jews safe. Most of the members were young in age, and they took necessary precautions in order to remain safe and unidentified. Annemarie's sister, Lise, and Lise's fiancé, Peter, were both members of the Resistance. It is only after Lise's death that her family comes to understand the truth about their involvement in the organization.