Æ20 - Valerian and Gallienus COL AVGO, TROA

Alexandria Troas held colonial status under Rome — formally Colonia Alexandria Augusta Troadensis — a rank granted to ease military resupply along the Aegean coast. The joint reign of Valerian and Gallienus, father and son ruling simultaneously from 253, produced an extraordinary volume of provincial bronze across Asia Minor, partly because the imperial mints were increasingly consumed by the military emergency on the Rhine and Danube frontiers. Local colonial issues filled the gap.

Valerian's capture by Shapur I of Persia in 260 effectively ended the joint reign and terminated most provincial coinage of this type almost immediately.