Heyer essentially established the historical romance genre and its subgenre Regency romance. Her regencies were inspired by Jane Austen. To ensure accuracy, Heyer collected reference works and kept detailed notes on all aspects of Regency life. While some critics thought the novels were too detailed, others considered the level of detail to be Heyer's greatest asset. Her meticulous nature was also evident in her historical novels; Heyer even recreated William the Conqueror's crossing into England for her novel The Conqueror.

While in Tanganyika, Heyer wrote The Masqueraders, set in 1745. The book follows the romantic adventures of siblings who pretend to be of the opposite sex to protect their family, all former Jacobites. Although Heyer did not have access to all of her reference material, the book contained only one anachronism: she placed the opening of White's a year too early.