History shows that any changes within Christianity were reflected in the lives of many nations, and often the whole world as a whole. For example, the "Great" schism of the XI century. divided not only the previously one Church into Catholic and Orthodox, but also the whole of Europe - into Eastern and Western. Reformation of the XVI century. still determines the worldview of hundreds of millions of people and the policy of most states on earth. The monograph examines a topic that is little studied in Russian religious studies - church schisms. The reasons, course and consequences of religious divisions for the church, state and society are shown using the example of the Russian Orthodox Church of the XIV - early XXI centuries. The book also provides a historical and religious analysis of the phenomenon of religious schisms and makes an attempt to typologize them. The monograph is intended for religious scholars, historians, teachers, undergraduate and graduate students, as well as anyone interested in the history of religion.