The article was prepared on the basis of a study of the works on the history of Christianity, written by Russian researchers in the second half of the XIX – early XX century. In the history of the study of Christianity in Russia in the period under review, two areas are distinguished: confessional and academic, which was less affected by the church dogmatic tradition and sought to use critical methods. One of the reasons for the relatively late registration of the academic (secular) history of Christianity in Russia was the lack of a tradition of the existence of theological faculties within the universities and the concentration of the study of Church history within the spiritual schools, in which, on the whole, there was only an exclusively canonical attitude toward sources, mainly limited to the Holy Scriptures and the writings of the Church Fathers. Changes in the Russian “Church history science” would be impossible without changing the system of secondary and higher education. After the introduction of the new University Statute in 1863, the level of university teaching of the history of Christianity increased significantly, and the apologetic nature of teaching ceased to prevail in the training courses and in the writings of the faculty. There was no serious research on the history of Russia without touching upon the history of the Russian church; Russian historians explored the historical and ecclesiastical problems in the context of the history of Russia and the history of Russian culture. The history of Western Christianity was studied in Russia before the beginning of the twentieth century, practically, exclusively within the framework of comparative or accusatory theology, which was mainly concerned with the critical examination of the so-called “heterodox” confessions from the standpoint of Orthodox dogma.