AR25 - Antoninus Pius L ΚΒ

Year 22 of Antoninus Pius's reign, which this coin dates to, fell during one of the most administratively stable decades in Roman imperial history — a fact that makes Alexandrian billon tetradrachms from this period abundant in the archaeological record. The Egyptian mint at Alexandria operated under tight prefectural control, producing billon rather than silver because Rome had long since stripped Egypt of the right to mint true silver coinage, keeping its currency deliberately inconvertible with the rest of the empire.

Emmett 1428.22 is among the more commonly encountered regnal year designations for this type, consistent with the sustained output of the Alexandrian mint across Pius's unusually long 23-year reign.