AR22 - Marcus Aurelius L ΙΖ

Year 17 of Marcus Aurelius's reign fell during the immediate aftermath of the Marcomannic Wars, a grinding conflict along the Danubian frontier that had drained the imperial treasury severely enough that Marcus debased the silver content of the Roman coinage. The Alexandrian billon tetradrachm, already a localized fiduciary currency long divorced from its Ptolemaic silver origins, was effectively insulated from that particular pressure — Egypt's mint operated under its own closed monetary system, barring foreign coin and circulating its issues internally.

The L ΙΖ regnal year notation is the Alexandrian mint's standard dating mechanism, anchored to the Egyptian calendar year beginning in late August.