AR23 - Severus Alexander L ΙΒ

Year 12 of Severus Alexander's reign fell during a period of mounting military pressure on the eastern frontier, culminating in his campaigns against the Sassanid Persians under Ardashir I. The Alexandria mint continued producing tetradrachms through this turbulence largely uninterrupted — the Egyptian monetary system, insulated from the imperial silver coinage by deliberate Ptolemaic-era policy still honoured by Rome, kept its own closed circuit of exchange.

Dattari 4378 places this among a well-documented run, though die alignment and billon fineness vary noticeably across the year 12 issues.