AR20 - Diocletian L Ζ

This piece dates to regnal year 7 of Diocletian's reign over Egypt, a province that retained its own distinct dating system and mint long after the rest of the empire had standardized. Alexandria's output during this period was enormous — the mint was one of the busiest in the Roman world — yet survival rates for billon tetradrachms in collectible condition remain surprisingly low, owing to the alloy's chronic susceptibility to surface corrosion and pitting.

Year 7 falls just before Diocletian's currency reforms of 294 AD, which effectively ended the Alexandrian tetradrachm series entirely after nearly three centuries of unbroken production.