Year 17 of Antoninus Pius's reign — the regnal year encoded in that ΙΖ — fell during one of the most administratively stable decades the Roman empire would ever see. Alexandria's billon tetradrachm production under Pius was enormous by provincial standards, and the mint ran continuous annual issues throughout his reign, making the Emmett 1419 series among the better-documented Alexandrian sequences. The alloy had been quietly debased from earlier Trajanic standards, though year 17 pieces still carry enough silver content to distinguish them from the base issues that followed under Marcus Aurelius.
Year 17 of Antoninus Pius's reign — the regnal year encoded in that ΙΖ — fell during one of the most administratively stable decades the Roman empire would ever see. Alexandria's billon tetradrachm production under Pius was enormous by provincial standards, and the mint ran continuous annual issues throughout his reign, making the Emmett 1419 series among the better-documented Alexandrian sequences. The alloy had been quietly debased from earlier Trajanic standards, though year 17 pieces still carry enough silver content to distinguish them from the base issues that followed under Marcus Aurelius.