Successianus Successianus was a Roman general of the Third Century AD of whom very little is known for certain . He appears to have distinguished himself at a lower rank , but , when promoted to Praetorian Prefect by Valerian he failed to save his Emperor from defeat and capture by the Persia ns . Sources . What little is known of Successianius comes from the " Historia Nova " of Zozimus and the information is teased out by Prof . A . Alfoldi and by L . L . Howe . This article is based on their accounts . Origins . Nothing is known of Successianus ' s origins or his date of birth . The absence of any evidence as to his " nomen " means that onomastic analysis cannot be applied . Career . Successianus is first encountered in as commander of the garrison of Pityus on the eastern coast of the Black Sea in modern Georgia . This region did not lie within the Roman imperial frontier , but it is known that Rome was in a treaty relationship with the local communities and supplied garrisons at key points . During Successianus ' s watch , Pityus came under attack by the " Borani " , one of the peoples who lived in the steppes north of the Crimea known generally as the " Scythae " . The " Borani " raid on Pityus was one of the first of the seaborne expeditions by the " Scythae " which were to reach their peak in the 260s . Thanks to Sucessianus ' s inspired leadership , the city held out and the raiders were forced to retreat after suffering considerable losses . This rare success by one of his commanders inspired the Emperor Valerian who had recently arrived in Syria to take charge of the war against the Persians to call Successianus to his headquarters in Antioch , where he is said to have assisted the Emperor in rebuilding the city which had been reduced to ruins by King Shapur . He is then supposed to have been made Praetorian Prefect although Zozimus nowhere says this . If he was thus promoted , his authority is likely to have been confined to those provinces under Valerian ' s direct control – i . e . Asia , Mesopotamia and Syria – while Silvanus may have acted for Gallienus in an equivalent office . End . Unfortunately , the qualities that had made Successianus an excellent garrison commander in Pityus were not those he needed as Chief - of - General Staff at Valerian ' s shambolic headquarters : the Roman defence of the East , torn between the need to fend off Shapur in Mesopotamia and Syria and the " Scythae " in Asia Minor , was generally ineffective . Unable to battle the deadly combination of military defeat and plague military " morale " seems to have collapsed . It is supposed that Successianus was with Valerian , still serving him as Praetorian Prefect when Shapur defeated him and took him captive near Edessa in June ( ? ) 260 . It is supposed that , like his Emperor , he died in Persian captivity . It is impossible to determine whether in Successianus we see a promising young man promoted beyond his capabilities or a soldier of some competence who was not allowed to exercise his talents or some combination of the two . It was Rome ' s tragedy that there was to be no removal of Valerian to make way for a competent soldier as occurred in the case of his son Gallienus when , arguably , the need was so much less pressing .