Antoninianus - Diocletianus SAECVRIT PERP or SECVRIT PERP, Securitas

Diocletian's currency reform of 294 AD — the introduction of the argenteus and the restructured numismatic system under the tetrarchy — renders coins like this one historically precise markers of the moment just before everything changed. Struck in the two years immediately preceding that reform, this antoninianus belongs to the last coherent phase of a denomination that had itself been debased so aggressively since the 260s that its silver content had fallen to a thin surface wash over base metal. Diocletian had not yet solved that problem when these were struck.