About the book: 1874 / for a long time I painstakingly and purposefully collected historical materials about the development of Ukrainian statehood and culture. P. A. Kulish’s fundamental study “The History of the Reunification of Rus',” on which he worked for almost ten years, was first published in 1874. In this work, P. A. Kulish voices the idea of ​​the historical in the 17th century. Since such a presentation of history contradicted the principles of the Soviet system, the works of P.A. Kulish were banned in the USSR, and his name is practically unknown to readers. The reader is invited to the second volume of “The History of the Reunification of Rus'” by P.A. Kulisha. It contains chapters XI to XX. At the beginning of the second volume, the author writes a short preface to the publication of the first two volumes of his book. In Chapter XI, the author talks about (by this term historians understand the period from 1569 to 1667 for the possession of Western Russian lands). In the second volume, the author includes historical information about when the Koshevoy Ataman, Hetman of the Zaporozhian Army, died from wounds. As an appendix to the second volume, Polish texts and his son Janusz to the prince, in honor of Rus', are given. Historical research by P. A. Kulish sheds light on unknown points .