Although she was brought up in the Church of England, Jacob converted to Roman Catholicism at around the age of eighteen. But she remained proud of her Jewish heritage. This is most clearly demonstrated in The Gollantz Saga, which she began writing just before the Nazis swept to power in Germany. Beginning in early nineteenth century Vienna, it follow several generations of a Jewish family, as the head of the house establishes a business and life in England, moving among the British upper classes. The series is an engaging and warm exploration of family ties and rivalries, and the principles of honour and loyalty.