The first alleged bishops of Cherson – Ephraim, Basileos, Eugenios, Agathodor, Elpidios, Aitherios, and Kapiton – are fundamental figures for the Church history of Chersonesus-Cherson, in southern Crimea, and the whole Northern Black Sea coast. The accounts of miracles and martyrdom of these missionary bishops are placed in the fourth century. However, the hagiographic tradition itself is not contemporary to the described events and has been established in different phases, ranging from the middle of the 5th to the second half of the 9th century. This talk addresses the challenges of building a prosopographical dossier for a group of persons whose historicity might be dubious and based on heterogeneous, multilayered and multilingual sources. It also seeks to place this dossier in the context of data on the Late Antique Christian communities of the Northern Black Sea coast built from epigraphic sources, as a part of the prosopographical work within the DANUBIUS Project.