The book is devoted to the history of the text of the "Tale of Bygone Years," determining which parts of it were written when and by whom. The author is building a reconstruction of the history of manuscripts of the "Tale of Bygone Years" in connection with the history of the annals of the XII-XIV centuries. In the text of the initial chronicle, the author identifies several groups of lexical, syntactic and other features that he proposes to attribute to the style markers of different authors; based on this, an attempt is made to stratify the text of the "Tale of Bygone Years" in as much detail as possible and reconstruct the history of the initial annals.