The paper turns to some disputable questions dealing with certain events and dates: Dio Chrysostom’s visit to Olbia, recitation of the Borysthenitic Discourse in Prusa and the time of the Getic invasion. The author discusses Yu.V. Vinogrados’s, S.D. Kryzhitsky’s and V.V. Krapivina’s ideas considering the reliability of the information on Olbia, its citizens and the barbariabs given in the introductory part of the speech as compared to archaeological sources. Special attention is paid to the erroneous parallels drawn between the large number of barbarians mentioned by Dio and Olbian epigraphic monuments, most of which are not contemporary to Dio’s account. The existing data allow the author to suppose that Dio’s visit to Olbia could be regarded as a starting point of a new period of its historical development and the basis for the assessment of deep changes which took place in the late 1st and early 2nd centuries BC in Olbia’s political and cultural life after Dio’s departure, when bearers of non-Greek, mainly Irano-Sarmatian names appeared among not only the citizens, but also the city elite. These ethnical and political changes, however, did not imply a sarmatization or barbarization of Olbian cultural life in the first centuries of the Christian era.