Part of Constantinoupolis on the web section of Elpenor's history resources
The Bulgarians of the Danube, the Moravians, and the Slavonians of Illyria had been already enlightened by holy baptism about the middle of the ninth century, during the reign of the Greek emperor Michael and the patriarchate of the illustrious Photius. St. Cyril and St. Methodius, two learned Greek brothers, translated into the Slavonic the New Testament and the books used in divine service, and according to some accounts even the whole Bible.
This translation of the Word of God became afterward a most blessed instrument for the conversion of the Russians, for the missionaries were by it enabled to expound the truths of the Gospel to the heathens in their native dialect, and so win for them a readier entrance to their hearts.
Oskold and Dir, two princes of Kieff and the companions of Ruric, were the first of the Russians who embraced Christianity. In the year 866 they made their appearance in armed vessels before the walls of Constantinople when the Emperor was absent, and threw the Greek capital into no little alarm and confusion. Tradition reports that "The patriarch Photius took the virginal robe of the Mother of God from the Blachern Church, and plunged it beneath the waves of the strait, when the sea immediately boiled up from underneath and wrecked the vessels of the heathen. Struck with awe, they believed in that God who had smitten them, and became the first-fruits of their people to the Lord." The hymn of victory of the Greek Church, "To the protecting Conductress," in honor of the most holy Virgin, has remained a memorial of this triumph, and even now concludes the Office for the First Hour in the daily Matins; for that was, indeed, the first hour of salvation to the land of Russia.
Cf. Al. Vasilief, A History of the Byzantine Empire * Pavle of Serbia, 550 years since the Fall of Constantinople * Constantelos, Greek Orthodoxy - From Apostolic Times to the Present Day * Dostoyefsky, Constantinople can not but belong to Russia! * Meyendorff, Christ as Word Gospel and Culture * George Majeska, Russian Pilgrims in Constantinople (pdf) * Pan. Christou, The Missionary Task of the Byzantine Emperor * Toynbee, Christianity and Civilization * Gogol, We recognise in them the divine origin of man * Saint Silouan the Athonite * Papacy : The Plague of Christianity * The Orthodox Church
Elpenor's Bilingual (Greek - Russian) New Testament
The Greek Word Library
Reference address : https://www.ellopos.net/elpenor/greek-texts/fathers/mouravieff-russia.asp?pg=2