AR24 - Antoninus Pius L ΚΒ

Year 22 of Antoninus Pius's reign — 158-159 AD — falls deep into one of the most administratively stable periods Roman Egypt ever experienced. The Alexandria mint was producing tetradrachms at a controlled, systematic pace under prefectural oversight, and the billon alloy by this point had degraded significantly from the near-pure silver of early imperial Alexandrian issues. Nero's debasement a century earlier had set that trajectory irreversibly in motion.

The Emmett 1428.22 is not a rare type, but year 22 pieces in collectible condition are modestly harder to locate than mid-reign dates.