Æ18 - Valerian and Gallienus ΠΩΡΟϹΕΛΗΝΕΙΤΩΝ

Poroselene was a small island community off the Aeolian coast, administratively folded into the Pergamene conventus — the Roman judicial district centered on Pergamum. Its civic coinage is sparse, and issues naming both Valerian and Gallienus as co-emperors narrow the window sharply to the period between Gallienus's elevation in 253 and the capture of Valerian by Shapur I at the Battle of Edessa in 260. After that humiliation, joint titulature became meaningless overnight.