The paper deals with one of the eighteen preserved homilies of St. Photius of Constantinople. Sermon of this holy Patriarch was told about 860 years, but the immediate cause was the attack the Russians at Constantinople. St. Patriarch is an eyewitness to this event and everything that happened before and after that, so that’s the homily, and there are two preserved – the third and fourth, that can be considered as an important historical source that informs about the beginnings of the relationship of Russians with Byzantium, and about Christianization of the Russians and southern Slavs. Translations of the Homily is very important because of the description of residents of the capital in the 9th century. Hence, the text and content of the homily have several layers and is very important as a primary theological and also historical source.