The History of the Empire from the Death of Marcus of Herodian in eight books, written in Greek, is a key source for the period from the reign of Commodus (AD 180) to that of Gordian III (238). Herodian is an eyewitness and the only contemporary historian whose work has come down to us in full. His point of view is all the more valuable because he is an outsider with respect to both court historiography, whose flattery he stigmatized, and to senatorial historians, represented mainly by Cassius Dio and by the biographies in the Historia Augusta. Nonetheless, Herodian has often been harshly criticized as a historian. This volume aims to shed light on the different areas and themes in which his historical work moves - literary technique, political lexicon, religious conception, geographical space, economic, political, cultural and military themes - to better understand the relevance of his historiographical approach and his historical thought.