A biography is an account of the course of someone's life, especially one published, that may include the person's date birth, others facts or dates, family, figures that influenced them, story elements, and their experience in education, relationships, and work. So, since a biography is an account of someone's life that needs to be as accurate as possible, to include imaginative or fake details, the biography would lose its credibility.
The Capulets and the Montagues in Romeo and Juliet are two families that are enemies. They apparently have an "ancient grudge" that is most likely irrational.
