AR25 - Antoninus Pius L ΚΓ

Year 23 of Antoninus Pius's reign — 159/160 AD — falls near the administrative peak of Roman Egypt's most stable imperial period. Alexandria's billon tetradrachms from this regnal year were struck under the prefect's authority as part of a closed currency system: Ptolemaic-descended coinage that could not legally circulate outside Egypt, forcing all incoming silver to be exchanged at the nome banks and restruck into this debased local fabric. The Dattari reference traces to Giovanni Dattari's early 20th-century Cairo collection, the single largest systematic hoard of Alexandrian tetradrachms ever assembled.