The monograph is the result of many years of W.’s research on the Church-State relations. In his work, based on the analysis of numerous sources, the author sets some questions of the relationship between law, power, canonic law, and philosophical and religious ideas about power and scrupulously analyzes them. A real bestseller, the book was sold out in 1916 in four months. The uniqueness of this work is not only in its rather provocative character for its time – the question of the ‘limits of Tsar power’, but, first of all, in the brilliant knowledge of Old Russian written sources, theology, history of political ideas, history of the legal thought both Byzantine and Old Russian one, as well as West European ideas. The monograph consistently proves the influence of the New Testament tradition and Orthodox theology, as well as the canonic law of the Orthodox Church on the formation of the Church-State relations and ideas about Tsar power in the Old Russian tradition.