AR22 - Valerian and Gallienus L Ζ

The joint reign referenced by this coin ended abruptly in 260 AD when Valerian was captured by the Sasanian king Shapur I at the Battle of Edessa — the first Roman emperor ever taken prisoner by a foreign enemy. Gallienus ruled alone thereafter, never negotiating his father's release. The Egyptian mint at Alexandria, which produced this piece, continued operating through the chaos of the subsequent "Crisis of the Third Century" largely uninterrupted, its output tracking regnal years through the L-date system that places this coin in year seven of the joint reign.