The ancient Romans had a custom of referring to sons born after the death of their father as "Postumus." This book could be called "Postumia." It appeared after the death of Nadezhda Feliksovna Ostromentskaya, known to young readers from the story "The Adventures of a Boy with a Dog." The new book remained unfinished. It was added by the historian A. Nemirovsky. So this story of the life of the young Roman Gavius ​ ​ was born, full of exciting adventures and full of tragedy. called the "veteran Caesar," but he became a warrior of Spartacus and shared the fate of the participants in the greatest slave uprising in history.