Westerfeld considers his novel to be an “alternate history” (260). Many of the basic events of the book are true to history, but many were altered or made up entirely. On June 28, 1914, Archduke Franz Ferdinand, the heir to the Austria-Hungarian throne, and his wife, Sophie Chotek, were shot to death by Serbian nationalists in the afternoon. Bending history, Westerfeld plotted his novel to begin at night, and in the story, the Archduke and his wife are poisoned, not shot. While rumors spread at the time that Germany was secretly behind the murders, very few historians believe them to be true. The real Archduke Ferdinand and Sophie had three living children, Sophie, Maximillian, and Ernst. Alek is completely fictional, but his struggle to inherit the kingdom is based on truth. In real life, the Archduke and Sophie were never able to legalize their marriage, so their children did not inherit any of their father’s property or titles. This is a major struggle for Alek’s character, and the tension between his royal upbringing and common blood characterizes his journey from boyhood to manhood.

Charles Darwin is also a real person whose contributions to science laid the framework for modern biology. Darwin proposed that all species descend from common ancestors, and his research helped establish the field of evolutionary biology.