Æ23 - Gordian III P M S COL VIM, AN I

Viminacium's colonial bronze coinage is unusual in the Roman provincial series for carrying an explicit year count — the AN I on this piece marks the first year of the colony's own era, inaugurated in 239 AD when Gordian III granted Viminacium the status of a Roman colony. The elevation was almost certainly tied to the city's strategic importance as a legionary base on the Danube frontier, home to Legio VII Claudia, at a moment when Gordian's guardians were scrambling to stabilize the northern borders following the chaos of the Year of the Six Emperors.

The sequential dating system makes Viminacium bronzes unusually trackable across reigns — a rare administrative transparency in provincial coinage.