Quinarius - Constantius I as Caesar PRINCIPI IVVENT or PRINCIPI IVVENTVT

The quinarius denomination had been largely moribund for centuries before Diocletian's reforms began reshuffling the Roman silver coinage hierarchy in the 280s. This piece belongs to the awkward transitional window before the argenteus was introduced around 294, when the quinarius occupied an uncertain position — struck in debased silver that bore little resemblance to its Republican ancestors. Constantius held the rank of Caesar under the Tetrarchic arrangement formalized in 293, making the dating of this type one of the more contested points among specialists, with some placing the earliest strikes as far back as the joint reign of Carinus and Numerian.