Andrew G. Scott
Herodian opens his ab excessu divi Marci with normative historiographic claims, drawn primarily from Thucydides (see Hidber 2006, 72-115; Kemezis 2014, 230-234). His history will focus on the changes of emperor over a period of sixty years; it was written from what Herodian saw, heard and experienced; and it is filled with events within his readers' memories (1.1.3, 1.2.5). Herodian also states that he will focus on the large number of changes in power that occurred in his day, specifically noting the difference between the older and younger emperors. For Herodian, the older emperors ruled themselves and their subjects with greater care, whereas the younger ones lived more carelessly and instituted many changes (1.1.6).
These ideas coalesce in the depictions of young emperors, which Herodian enhances with a visually oriented narrative (cf. Potter 1999, 87-88). Herodian specifically calls attention to the innovations of young emperors either by explicit claims of autopsy or an increased use of visual vocabulary, or a combination thereof. Examples include Commodus' performance in the arena, to which Herodian claims to have been an eyewitness (1.15.4); Caracalla's adoption of an Alexander-persona, which Herodian claims to have observed in the emperor's statues (4.8.2); and Elagabalus' use of a painting to prepare the Romans for his initial arrival into the city as emperor (5.5.6-7; see Zimmermann 1999, 222-232 for descriptions of imperial dress as part of Herodian's depiction of the emperors as tyrants.).
Herodian's assertion of eyewitness status has been used to judge the author's whereabouts during the period in question, and also to argue for other eyewitness reports even when explicit claims are not made (see most extensively Whittaker 1969, xxxi-xxxv). Yet Herodian's assertion that he saw Commodus performing in the arena is most likely false, based both on his presumed age and the passage's similarity to a parallel report in Cassius Dio (Kolb, 1972, 25-27; Sidebottom 1998, 2782). While this untruth might make us question whether Herodian can ever be trusted as an actual eyewitness of the events he reports, it should also turn our attention to the historiographical aspects of such posturing (cf. Sidebottom 1998, 2789; see also, generally, Pitcher 2009, 84-91).
These visual aspects serve a particular historiographic function, as they turn the reader into a virtual eyewitness and thus a proper judge of the author's initial claim about the activities of the younger emperors. The visual aspect is initially set up by one of the opening passages of the work (1.3.1-5), in which Marcus Aurelius, on his deathbed, feared the images of tyrants (τοιαύτας... τυραννίδος εἰκόνας) that he saw as he anxiously looked forward to the accession of his son Commodus (1.3.5). Herodian thus establishes his readers as the future viewers of these young tyrants as they appear in his history, and he highlights their innovations through vivid descriptions of their self-presentation.
Like Marcus Aurelius, both the Romans and Herodian's readers are able to see and recognize young tyrants, as in the examples of Commodus and Caracalla. Yet as the history progresses, the sense of sight, which previously had identified young tyrants by their appearance, loses its power. Elagabalus is able to persuade the Romans to accept his new image, at least temporarily. The end of the work highlights this failure, with its foreboding conclusion: "And so Gordian, who was about thirteen years old, was received as emperor and took control of the Roman empire" (ὁ δὲ Γορδιανὸς περὶ ἔτη που γεγονὼς τρισκαίδεκα αὐτοκράτωρ τε ἀνεδείχθη καὶ τὴν Ῥωμαίων ἀρχὴν ἀνεδέξατο, 8.8.8). By this time the accession of young emperors is no longer innovative but usual. Herodian thus seems to have exploited historiographic norms to develop an analytical tool for his readers and also to demonstrate the instability of autopsy in judging affairs in real time.