AR23 - Antoninus Pius L ΔωΔΕΚΑΤΟΥ

Alexandria's billon tetradrachms were struck to a deliberately debased standard kept separate from Rome's silver coinage, allowing the imperial administration to maintain a closed currency system in Egypt — coins entered the province and were reminted, but none left legally. The regnal year inscription ΔωΔΕΚΑΤΟΥ places this piece in year 12 of Antoninus Pius, a reign so administratively stable that ancient sources struggled to find drama in it.

The billon content by this period had dropped well below 25% silver, a slow degradation that had begun under Nero's provincial reforms a century earlier.