AR22 - Gallienus sole reign) (L ΙΓ

By year 13 of Gallienus's reign — reckoned from his co-emperorship with Valerian beginning in 253 — the Alexandrian mint was operating under conditions of severe monetary debasement. Billon issues of this period contain dramatically less silver than earlier tetradrachms, part of a empire-wide collapse in coinage quality that accelerated sharply after Valerian's capture by Shapur I in 260 left Gallienus sole ruler managing simultaneous frontier crises on multiple fronts. The Cologne, Dattari, and Milne references aligning on this piece confirm a well-documented emission rather than a transitional or mule strike.