This paper focuses on the use of the “exemplum” of Alexander in seven Imperial speeches by Libanius (4th c. AD). These are studied and analysed under both a macro- and a micro-perspective: in the first case, the analysis highlights the individual historical examples, their rhetorical function and their literary form. These aspects are subsequently discussed with respect to the specific literary genre, the position of exempla within the speech structure, as well as their aims and impact. Of special interest are the different ways in which Libanius uses the sometimes positive and sometimes negative image of Alexander in order to reinforce his argumentation and to guide his rhetorical strategy in specific pathways.