56 A less likely explanation in my opinion but one at least deserving of consideration is that legio Arabica is to be understood as the actual name of a legion as with the various legions called Italica, Parthica, Gallica, Cyrenaica, Scythica,Macedonica. No such legion is of course otherwise known and the best one might propose is that the new legions of Severus, or some of them, originally bore names other than I, II and III Parthica. The two new legions of Marcus Aurelius, for example, were originally called Pia and Concors (ILS 2287), and, as we have seen, the earliest reference to one of the new Severan legions called it simply legio Parthica. Is it possible that Severus originally called his new legions Arabica,Parthica and, perhaps, Adiabenica?, only later, after the Second Parthian War, changing the names? However, as the referee of this article observes to me, the usage of the Historia Augusta requires that the legion’s name be normally complemented either by its numeral (e.g. Hadr. 3.6) or its domicile (Sev. 5.1, 6.7; Av. Cass. 5.5).