The holocaust narrative and stories are based on actual stories told to the director by his Polish grandparents, who were personally involved with hiding Polish Jews from the Nazis during World War II.
The lead character Apollonia Kowalski is strongly based on the silent film actress Pola Negri, and even named the character after her (the name Pola is a contraction of Apollonia). Director Kotowski built the Apollonia Kowalski character to be one that he imagined Negri would enjoy playing as an old woman.