Askold and Dir
The Rus' attack on Constantinople in June 860 took the Greeks by surprise, "like a thunderbolt from heaven," as it was put by Patriarch Photios in his famous oration written for the occasion. Although the Slavonic chronicles tend to associate this expedition with the names of Askold and Dir (and to date it to 866), the connection remains tenuous. Despite Photius' own assertion that he sent a bishop to the land of Rus' which became Christianized and friendly to Byzantium, most historians discard the idea of Askold's subsequent conversion as apocryphal.