AR22 - Antoninus Pius L ΙΘ

Alexandrian tetradrachms dated to Year 19 of Antoninus Pius (155–156 AD) fall within one of the most administratively quiet reigns in imperial history — which is precisely why the Alexandria mint kept busy with an unusually rich rotation of reverse types, cycling through deities, personifications, and zodiacal series to fill the calendrical issues. The billon content of these pieces had been declining steadily since the Neronian debasement of the late 1st century, and by the mid-Antonine period the silver content was low enough that "billon" is generous.

Milne 2243 places this among a well-documented but not rare subgroup for the regnal year.