Cyprian, an educated Hesychastic-oriented monk, was one of the most important representatives of the Orthodox church in medieval Eastern Europe. All of the measures which he carried out during his time as the Metropolitan of Kiev were aimed at maintaining the unity of the metropolis, covering the whole of Eastern Europe, regardless of political divisions. He used proposals for negotiating a church union to find a solution to the situation which had arisen after the foundation of the Polish-Lithuanian union, which presented the Orthodox church with a new situation. He continued the reforms to the monasteries in the Grand Duchy of Moscow, which helped create the conditions for the development of the Russian autocephalous church. After a critical period in the 1380s, he contributed towards the restoration of the authority of the Russian metropolis and the entire ecclesiastical hierarchy.
The study deals with the Role of Iosif of Volokolamsk in the formation of the relationship between church and state at the turn of the 15th and 16th century. Shows that Iosif in his concept of building a Russian society as the orthodox wouldn't give the church of state power. It also emphasises the role of Iosif of Volokolamsk as a monastic reformer.