Abstract: This publication gives an overview of I. I. Nazipov’s monograph dedicated to the complicated and insignificantly studies question of the Russian historical and historical-legal science – the political-legal connections of the principalities of Northeastern Rus’ and Horde of Ulus of Jochi. The author of the monograph, based on the absence or presence of the signs of states, made an attempt to determine the level of state subordination of the Russian lands in the XVIII-XV centuries to the Horde. At the same time, I. I. Nazipov leans on the research of peculiarities of the medieval reality that influences the content of the signs of state: religiousness, social hierarchy of medieval society, spatial narrowness of the worldview, lack of the idea of national unity. The presented in monograph positions are of scientific interest due to understanding of the main forms of connections between the Hord and the Russian principalities. Based on analysis of these connections and intensity of their manifestation during the separate periods, the author determines the presence of signs of the state unity of Russian lands and the Horse, or their weakening. The monograph is first to collect and generalize the material about the military cooperation of Russian principalities with the Horde. The work systematized the forms of military aid of the Horde to the Russian lands on deflection of aggression from the Western States.