Æ31 - Marcus Aurelius L ΙΒ

Year 12 of Marcus Aurelius's reign — regnal year ΙΒ by Alexandrian dating — fell during the grinding Marcomannic Wars on the Danube, a conflict that consumed imperial resources and attention for most of the 160s and 170s. The Alexandrian mint continued operating on its own closed currency system throughout, its bronze issues inconvertible with Roman imperial coinage and intended purely for Egyptian internal circulation. Egypt functioned essentially as a monetary island within the empire.

The L ΙΒ date formula is the cataloger's primary tool for anchoring these bronzes chronologically, since Alexandrian regnal years ran from the Egyptian new year in late August.