Dionysius' letter to Germanus is a valuable document because it allows insights into the practice of exile at the times of the persecution under the emperor Valerian. The paper will present observations concerning the bishop's activities in exile, the conditions he was subjected to, his relation to the imperial authorities, to the people at his place of banishment and to those from his church in Alexandria. It will also deal with Dionysius' theological interpretation of his exile. Finally, the paper will draw a comparison with a case of exile in the fourth century and will ask for continuities and discontinuities in the phenomenon of clerical exile before and after Constantine. The paper is part of the conference workshop WS 0146 "Clercial Exile in Late Antiquity".