AR22 - Valerian and Gallienus L Γ

This tetradrachm was struck during the sole co-regency year marked by regnal year Γ (year 3), when Valerian and Gallienus were jointly managing an empire under simultaneous pressure on two fronts — Shapur I's Sasanian campaigns in the east and increasing Gothic incursions across the Danube. The Alexandrian mint never stopped producing; Egypt's grain supply made it too strategically vital to allow monetary disruption, and the prefect's authority kept the mint running regardless of who held the purple in Rome.

Billon content in Alexandrian tetradrachms had been declining steadily since Caracalla, and by year 3 of Valerian the silver fraction was negligible — a fact the population almost certainly understood.