This collection of articles is an additional volume to the previously published 5-volume book by A.M. Velichko “History of the Byzantine Emperors”, which provides more in-depth research on the issues discussed in this work. All of them, to one degree or another, relate to the idea of a “symphony of powers”, the relationship between priestly and political authorities, the Church and the state in various periods of the existence of Christian civilization - both in Byzantium (the Holy Roman Empire), and in the West, and in Russia. The book provides examples of various historical forms of “symphony” and focuses on the active participation of the supreme authority in the activities of the Church and in church government. The author paid special attention to such a multifaceted phenomenon of the political life of mankind as an empire. Of no less interest are works devoted to understanding the idea of law in Byzantium and Russia. The book is intended for a wide range of readers interested in the history of the Church and the state, and is also intended for students and teachers of historical and legal higher educational institutions.