The Books of Jacob is based on a true story. Jacob Frank was a Polish Jewish religious leader and messianic claimant who, after an eventful life that included multiple conversions and exiles, became the leader of a large sect of Sabbatian followers in eastern Europe, colloquially referred to in the novel as the Contra-Talmudists, the neophytes, or simply Jacob’s followers.

Jacob was born in Korolowka, Poland, in 1726 to a wealthy Jewish family. After the death of his father, he came under the influence of Sabbatai Tzvi, a Jewish mystic who claimed to be the Messiah. Jacob embraced Tzvi’s teachings and soon gathered a large following of his own, leading to his excommunication from the Jewish community. In 1755, Jacob converted to Catholicism and changed his name to Jacob Frank. He then traveled to Vienna, where he met with Pope Clement XIII and convinced him to grant religious freedom to him and his followers.

Jacob then moved to Offenbach, Germany, where he established his own religious sect, which preached a faith that combined elements of Christianity, Islam, and Judaism. He also taught his followers the doctrine of reincarnation and the belief that he was the reincarnation of the biblical Jacob.