AR23 - Severus Alexander L ΙΓ

Year 13 of Severus Alexander's reign fell during a period of mounting pressure on Rome's eastern frontier, where Ardashir I had recently overthrown the Parthian Arsacids and founded the Sassanid Empire — a far more aggressive neighbor. Alexandria's mint continued producing billon tetradrachms on its own reckoning, tying issues to regnal years rather than the Roman consular calendar, which makes dating these pieces unusually precise by provincial standards. The billon content by this period had degraded considerably from earlier imperial-era Egyptian coinage.