Æ28 - Valerian and Gallienus ΑΡΤΕΜΙϹ ΕΦΕϹΙΑ

Ephesus retained the right to strike civic bronze through the joint reign of Valerian I and Gallienus, a privilege the city leveraged aggressively — Ephesian output during this period is among the densest of any Asian mint, reflecting both the city's negotiating power with Rome and its need to supply coinage for a region increasingly destabilized by Sassanid raids into Asia Minor. Valerian himself was captured by Shapur I at Edessa in 260, the only Roman emperor taken prisoner in battle, an event that effectively ended this co-reign issue.