Æ25 - Valerian and Gallienus ΚΛΑΖΟΜΕΝΙΩΝ

Clazomenae, a coastal city on the Ionian peninsula, had been a functioning mint under Roman provincial authority for generations by the time Valerian and Gallienus issued coins jointly — a pairing forced by military necessity when Valerian elevated his son as co-emperor in 253 to manage the western empire while he confronted mounting threats in the east. That arrangement ended abruptly in 260 when Valerian was captured by Shapur I at the Battle of Edessa, the only Roman emperor ever taken prisoner by a foreign enemy. Provincial mints in the Smyrna conventus largely ceased striking in his name immediately after.