AR18 - Diocletian L Δ

Year 4 of Diocletian's reign in Egyptian reckoning — L Δ marking the regnal year in the Alexandrian dating system that persisted through the Roman period. Egypt operated a closed currency zone under Rome; provincial coinage circulated internally and could not legally leave the province, a system that survived largely intact until Diocletian's currency reform of 296 AD abolished the Alexandrian mint's autonomous output entirely and folded Egypt into the empire-wide monetary system for the first time.