The article examines the apostolic mission in the Dnieper and Northern Black Sea regions, reveals its geographical boundaries, objects and subjects of missionary activity through the examination of three types of historical sources: Christian apocrypha (Syrian, Coptic, Ethiopian and Slavic); analysis of the works of Byzantine historians (Eusebius of Caesarea, Eucherius of Leon, Hippolytus of Rome, Dorotheus of Tyre, Epiphanius of Cyprus, Simeon Metaphrastes, Nicetas of Paphlogonia and Nicephorus Callistus). This problem is also considered through the prism of the Russian chronicle collection; the following lists were analyzed:: Laurentian, Trinity, Ipatiev, Sofia, Nikon, Tver, Simeon, Lvov Chronicles and the Book of Degrees. When analyzing the source study and historiographic material concerning the study of the areas visited by the apostles in the Dnieper region and the Northern Black Sea region, it was assumed that their missionary object was not only the Slavic tribes, but also all the peoples living in the region during this period, including the ancestors of the modern Adyghe, to whom a number of experts also include the Zikhs. For a comprehensive analysis of the problem under study, comparative and problem-chronological methods of historical research were used. With a comprehensive analysis of all three types of historical sources: Christian apocrypha, Byzantine writings and Russian chronicles, it can be stated without the slightest doubt that the southern region of Russia has a rich apostolic history. Taking into account the evidence provided in historical sources, it can be stated with complete confidence that the apostolic mission of Andrew the First-Called and his disciples was directed not only at the Slavic tribes, but also at the ancestors of the modern Adyghe - the Zikhs.