DIOCLETIAN'S MONETARY REFORM
Imperial Rome
by Enrico Forlanini

Diocletian's first act concerning coinage was to try and give back stability to the production of gold coins. About 286 A.D. he issued a new aureus weighing 1/60th of a libra (= about 5.40 grams). Previously he had issued - only at some mints - lighter gold coins weighing 1/70th of a libra (= about 4.68 grams) as indicated by the Greek letter O (= omicron) equal to the number 70. The reformed aureus - that sometimes bears the Greek letter Ξ (csi = 60) - represents the central part of the renewed bimetallic system introduced by Diocletian. This system was based on a new silver coin - commonly called argenteus - which was identical to Nero's denarius in weight and fineness. Smaller denominations were also issued in billon and copper.

During the Tetrarchy new mints were activated and many of them (Heraclea, Nicomedia, Thessaloniki) issued gold coins. In Egypt, the mint of Alexandria ceased issuing a provincial coinage about 296 A.D. and begin to produce imperial coins, including aurei . The practice of marks indicating the mint became common. These mintmarks are usually formed from the initial letters of the city and appear in the exergue of the coins. The letters SM before the initials of the mint stand for S(acra) M(oneta). Latin and Greeks letters or numerals can be added to indicate also the workshop.

Portraits become standardized and impersonal, following a style that conforms to Tetrarchic ideology. Reverses can be only epigraphic, mentioning the vota taken and fulfilled every ten or five years of reign. In Britannia the mint of Londinium issued aurei in the name of the two local usurpers Carausius and Allectus (286-296 A.D.).


Click on the images of the coins to enlarge them


Aureo
di Diocleziano

Aureo
di Diocleziano

Aureo
di Diocleziano

Aureo
di Valeria

Aureo
di Licinio I

Aureo
di Costantino I

Aureo
di Alletto
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