According to Historia, Trebellianus was a Cilician robber, who called his castle in the fastnesses of the Isaurian mountains the Palatium (as the imperial palace on the Palatine, in Rome), established a mint, and gave himself the title of emperor. But having been tempted to quit his stronghold and descend into the plain, he was there encountered and slain by Causisoleus, an Egyptian, one of the generals of Gallienus (dux Gallieni), brother of Theodotus who had defeated Mussius Aemilianus.