Double sesterce - Postume Victoria Aug

Postumus declared himself emperor in 260 AD after defeating — and almost certainly ordering the murder of — Saloninus, the young son of Gallienus, at Cologne. His breakaway Gallic Empire held together a Rhine frontier that the central Roman government was simply failing to defend, and his coinage reflects a ruler investing in legitimacy rather than improvisation. The double sesterce, a denomination he effectively revived and regularized, was struck in bronze at a moment when silver coinage had debased to the point of near-worthlessness.

Elmer 253 is a well-documented emission from early in his reign, when Postumus's minting operation was at its most prolific.