Æ21 - Valerian and Gallienus ΝΙΚΑΙΕΩΝ

Nicaea's civic bronze coinage under the joint rule of Valerian I and Gallienus reflects a moment when provincial mints were largely left to their own administrative devices — the emperors were perpetually occupied with military crises on multiple frontiers simultaneously. Valerian was captured by the Sasanian king Shapur I at the Battle of Edessa in 260, the only Roman emperor taken prisoner by a foreign enemy, which effectively ended this joint-reign period and terminated issues of this type.