The article deals with the relations between Olbia and the barbarians around it. The author points out Olbia’s close connections with the steppe and forest steppe zones of the North Pontic area. As a result, a part of the local population moved to the city and its chora, and some Hellenes settled in Scythian hinterland, where they were engaged in trade. The problem of the Callipidae is reconsidered in this light. The author maintains that this Scythian tribe had previously been nomadizing in the steppe areas north and northwest of Olbia, but in the late 6th – early 5th centuries BC, ousted by a new group of nomads, they moved to the forest steppe area together with some inhabitants of Olbia’s shrinking chora. Here the Callipidae became sedentary and took up agriculture, constituting together with the Greeks a group of population which Herodotus called Hellenic Scythians. They cannot, therefore, be identifi ed with the Mixellenes of the Hellenistic Olbia, the Mixellenes being Olbia’s allies against the Sarmatians and most probably inhabitants of Crimean Scythia.