This book tells the story of the birth of the great Christian civilization and the rebirth of the pagan Holy Roman Empire into the brilliant Byzantium. The book sets out the history of the reign of all Byzantine emperors of the 4th-5th centuries from the dynasties of Constantine, Valentinian, Theodosius, Leo, picturesquely and vividly narrates numerous political and church events, describes the acts of the I, II, III, IV Ecumenical Councils. In addition, the book is equipped with special appendices, which provide background material on the formation of the political and legal status of emperors, the “barbarian” world, the organization of the Roman army, as well as the administrative and church structure, and the characteristics of the dominant church departments of that time.