Diocletian: Bronze follis Coinage

Coinage Scope and Selected Issues

The Bronze follis coinage issued in the name of Diocletian includes issues distinguished by their portraits, inscriptions, reverse designs and mint attribution. This study concentrates on the Carthage SALVIS AVGG issues, rather than presenting one design as the entire denomination.

The issue dates and detailed iconographic descriptions below apply to the discussed groups, not automatically to every coin bearing the ruler's name. Other types and mints require their own catalogue comparison. An individual gallery coin must be assessed from its own inscriptions and institutional record; its measurements and provenance do not define the whole coinage.

Historical Context

Following decades of profound monetary debasement and political fragmentation during the Crisis of the Third Century, Emperor Diocletian introduced sweeping administrative reforms that established the collegiate Tetrarchy, or rule of four. Under this framework, two senior emperors (Augusti) ruled alongside two junior colleagues (Caesares) to secure the empire's far-flung borders. Maximian managed the western provinces, while Diocletian directed affairs in the East.

Between 294 and 296 CE, Diocletian enacted a major currency reform to restore stability and confidence in imperial coinage. The reform instituted a high-purity gold aureus, a fine silver argenteus, and a substantial, silver-washed bronze denomination known numismatically as the follis, though officially designated in contemporary administrative texts as the nummus. While established mints such as Rome, Trier, and Antioch predominantly struck the standard Genio Populi Romani reverse, the mint of Carthage in Africa Proconsularis emerged under distinct operational circumstances.

Founded around 296 or 297 CE, the Carthage mint was established directly to support Maximian's military campaigns against the Quinquegentiani, a confederation of five Berber tribes that had breached imperial defenses in Mauretania and Numidia. Maximian crossed personally to North Africa, pacifying the region through 297 CE and celebrating a formal adventus into Carthage in March 298 CE. To supply currency for the regional military presence and reorganize provincial taxation, the newly opened mint produced distinctive regional issues. Following initial celebratory issues, the mint settled into a major bronze production celebrating the harmony of the imperial college and the agricultural bounty of North Africa.

Selected Issues: Obverse: Iconographic Composition

The obverse composition displays the right-facing profile head of Diocletian, crowned with a laurel wreath (corona laurea). The wreath ties extend downward across the nape of the neck. Tetrarchic portraiture consciously broke away from the classicizing naturalism of the third century, adopting instead an austere, blocky aesthetic that prioritized institutional authority and collective solidarity over individual likeness.

Diocletian is rendered with a squared, heavy jaw, closely cropped hair, a neatly delineated short beard, and a deeply creased brow. These stylized facial planes emphasize mature discipline, vigilance, and gravitas. The composition is tightly centered within a fine, circular beaded border, establishing a visual uniformity shared by portraits of his imperial colleagues across all contemporary workshops.

Selected Issues: Obverse: Epigraphy and Inscriptions

The obverse legend encircles the imperial portrait along the beaded perimeter, beginning at the lower left and reading continuously clockwise:

• Script: Latin alphabet
• Language: Latin
• Lettering: IMP DIOCLETIANVS P F AVG
• Transliteration: Imp(erator) Diocletianus P(ius) F(elix) Aug(ustus)
• English Translation: Emperor Diocletian, Pious, Fortunate Augustus
• Placement: Encircling the portrait clockwise along the outer margin

This standardized titulature combines the military title of imperator with the traditional honorific virtues Pius (dutiful or pious) and Felix (fortunate or blessed), culminating in the supreme rank of Augustus.

Selected Issues: Reverse: Iconographic Composition

The reverse provides a striking departure from the standard imperial Genius motif, adopting an explicitly regional design dedicated to North African prosperity. The central device depicts the draped female personification of Carthage (Carthago or Felix Karthago). She stands facing frontally with her head turned gracefully in profile to the left, dressed in a long, high-girdled stola or tunic.

Her arms are held downward and extended outward to either side, with open hands supporting abundant clusters of freshly harvested fruits and agrarian produce. This visual metaphor directly celebrated North Africa's indispensable position as the primary grain basket and agricultural source for the western Mediterranean, emphasizing that imperial military security brought immediate civic and economic abundance.

Selected Issues: Reverse: Epigraphy and Inscriptions

The reverse inscription surrounds the personification within an outer beaded border:

• Script: Latin alphabet, employing the initial letter K for Carthage
• Language: Latin
• Lettering: SALVIS AVGG ET CAESS FEL KART
• Transliteration: Salvis Augg(ustis) et Caess(aribus) Fel(ix) Kart(hago)
• English Translation: With the Augusti and Caesars safe, Carthage is prosperous (or While the Augusti and Caesars are preserved, Carthage flourishes)
• Placement: Circumscribed from lower left to lower right

Beneath the standing figure, a clear ground line separates the field from the exergue. The four operating workshops (officinae) of the Carthage mint were allotted systematically among the four Tetrarchic rulers by collegiate seniority: workshop A (Alpha) was dedicated to the senior Augustus Diocletian, workshop B (Beta) to Maximian, workshop Gamma to Constantius Caesar, and workshop Delta to Galerius Caesar. First Tetrarchy emissions struck in Diocletian's name consistently bear solely the officina letter A in the exergue.

Typology and Documented Variants

The typological structure for this series was established in modern cataloguing by C. H. V. Sutherland in The Roman Imperial Coinage:

1. Group I, Small-Head Phase (c. 298-299 CE): Features a relatively compact, neatly proportioned portrait head of Diocletian. Reverse depicts Carthago standing holding fruits, with officina A in the exergue (catalogued as RIC VI Carthage 29a).

2. Group I Continued, Large-Head Phase (c. 299-303 CE): Retains the identical obverse legend and reverse composition, but the portrait of Diocletian is cut on a broader, heavier scale, occupying a greater portion of the die flan (catalogued as RIC VI Carthage 31a).

3. The AUCTA KART Emission (c. 298-299 CE): A scarce transitional variant where the reverse legend reads SALVIS AVGG ET CAESS AVCTA KART ("With the Augusti and Caesars safe, Carthage is augmented"), struck immediately following Maximian's victories (RIC VI Carthage 27a).

4. Field-Marked Emissions of the Second Tetrarchy (c. 305-306 CE): Following Diocletian's and Maximian's abdication, the reverse design continued under the new collegiate college. These later emissions introduced dynastic letters into the reverse left field: H (Herculius) for the lineage of Maximian, Constantius, and Severus II, or I (Jovius) for Diocletian, Galerius, and Maximinus Daia, while preserving the workshop letter in the exergue. Museum or dealer notations describing coins with letters such as H A in the exergue represent clerical conflations of these distinct field and exergual control marks.

Scholarly Debates and Attribution Limitations

The nomenclature and economic role of the reformed bronze coinage remain subjects of active discussion among numismatists. While the term follis has been widely adopted in modern usage, Kenneth Harl and C. H. V. Sutherland demonstrated that fourth-century documentary sources and administrative papyri referred to the denomination as the nummus. The term follis originally designated a sealed purse containing a fixed sum of coins, only later becoming a specific denominational label in the Byzantine era.

The tariffing of the nummus has also been clarified through epigraphic discoveries in Asia Minor. Michael Crawford analyzed the Currency Inscriptions from Aphrodisias and Aezani, which show that on 1 September 301 CE, Diocletian doubled the nominal tariff of the nummus (geminata potentia) from 12.5 to 25 denarii communes in an effort to curb escalating inflation immediately prior to issuing the Edict on Maximum Prices.

From a typological standpoint, isolating individual coins between Sutherland's small-head (RIC 29a) and large-head (RIC 31a) varieties presents inherent limitations. Because the flan diameter, legends, and exergual markings are identical, the distinction relies on subjective artistic scale that often reflects the individual die-cutter's engraving rather than a sharp chronological shift. Without comprehensive die-linkage studies, intermediate portraits occupy an overlapping typological boundary. Additionally, David Sear and other researchers have noted that early Carthage dies occasionally blend the iconography of Carthago with that of Abundantia or Annona, alternating between fruit clusters and cornucopiae or grain stalks.

References

1. The Roman Imperial Coinage, Volume VI: From Diocletian's Reform (A.D. 294) to the Death of Maximinus (A.D. 313). pp. 88-112, 411-417, 427-431
2. Online Coins of the Roman Empire: RIC VI Carthage 29a. Type RIC VI Carthage 29a
3. Online Coins of the Roman Empire: RIC VI Carthage 31a. Type RIC VI Carthage 31a
4. Online Coins of the Roman Empire: RIC VI Carthage 30b. Type RIC VI Carthage 30b
5. Online Coins of the Roman Empire: RIC VI Carthage 40a. Type RIC VI Carthage 40a
6. The New Empire of Diocletian and Constantine. pp. 49-64
7. Coinage in the Roman Economy, 300 B.C. to A.D. 700. pp. 148-158
8. Finance, Coinage and Money from the Severans to Constantine. Aufstieg und Niedergang der romischen Welt, II.2, pp. 560-593
9. Roman Coins and Their Values, Volume IV. pp. 49-52, 66 (nos. 12827, 12828)