Об управлении империей
The text known as "De Administrando Imperio" was written by emperor Constantine VII Porphyrogenitus, but he had at least one educated “Anonymous Collaborator”. Constantine VII’s direct appeals to his son Romanus II and Constantine’s first-person commentaries are located both at the beginning of the treatise in the Proem and in chapter 13, as well as at the end of the text, in chapter 51. In this text his son Romanus II is never designated as a self-sustained ruler. Obviously, the whole De Administrando Imperio Constantine VII was written when he was alive.