Gratian: Gold solidus Coinage

Coinage Scope and Selected Issues

The Gold solidus coinage issued in the name of Gratian includes issues distinguished by their portraits, inscriptions, reverse designs and mint attribution. This study concentrates on the two-emperors issues of Trier, 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

Flavius Gratianus was elevated to the rank of Augustus on 24 August 367 CE at Ambianum (modern Amiens) by his father, Valentinian I. This elevation created a collegiate imperial structure alongside Valentinian I and his uncle Valens, who governed the Eastern provinces. When Valentinian I died suddenly while on campaign at Brigetio on 17 November 375 CE, Danubian legions acclaimed Gratian's four-year-old half-brother, Valentinian II, as Augustus on 22 November 375 CE. Gratian accepted the collegiate settlement, retaining primary governance over Gaul, Hispania, and Britain, which he administered principally from Augusta Treverorum (modern Trier, Germany), while Valentinian II and his mother Justina were accommodated with court administrative spheres in Italy and Illyricum.

Augusta Treverorum functioned as a primary Western imperial residence and the foremost monetary atelier of the Valentinianic dynasty. The production of gold coinages at Trier met critical military and administrative obligations across the northern frontier: imperial accessional donatives, campaign bonuses, military salaries for the Rhine frontier garrisons, and payments to senior civil officials. The core denomination of this fiscal apparatus was the gold solidus, instituted under Constantine I at the statutory tariff of 72 pieces to the Roman pound of refined gold, with a theoretical weight of approximately 4.54 grams.

The solidi produced at Trier between the death of Valentinian I in November 375 CE and the death of Valens at the Battle of Adrianople on 9 August 378 CE constitute Trier Period III in late Roman numismatics. This emission represents one of the most prolific and strictly organized gold issues of the late fourth century, designed to affirm dynastic concord and imperial stability across the divided halves of the Roman realm.

Selected Issues: Obverse: Iconographic Composition

The obverse displays a right-facing portrait bust of Gratian, truncated at the lower chest. The imperial bust is attired in standard fourth-century ceremonial military dress, combining a decorated cuirass (lorica) visible at the chest and neck with an imperial mantle (paludamentum or chlamys). The mantle is draped over the left shoulder and gathered securely at the right shoulder by a prominent round, jeweled brooch (fibula) fitted with pendant pearls.

Gratian is rendered beardless, featuring the smooth, idealized facial planes characteristic of late Constantinian and Valentinianic court portraiture. His head is encircled by an imperial diadem secured at the rear of the head, with descending ribbon ties terminating in small round pearls. Within the documented emissions of Period III, two main diadem forms are distinguished:

• Pearl Diadem: Formed of two parallel bands of uniform pearls, constituting the primary obverse format of the series (RIC IX Treveri 39d).
• Rosette Diadem: Formed of circular jeweled segments or rosettes alternating with paired pearls, representing the continuation of earlier decorative conventions used during Period II (RIC IX Treveri 39c).

The complete obverse portrait composition is framed by a continuous, fine beaded border.

Selected Issues: Obverse: Epigraphy and Inscriptions

The obverse text is engraved in formal Roman square capital script following late imperial conventions:

• Script: Latin capital script
• Language: Latin
• Verified Lettering: D N GRATIA-NVS P F AVG
• Transliteration / Expansion: Dominus Noster Gratianus Pius Felix Augustus
• English Translation: "Our Lord Gratian, Pious [and] Fortunate Augustus"

The inscription begins at the lower left rim, ascends smoothly along the perimeter, divides symmetrically above the diadem ties over the imperial head (GRATIA-NVS), and curves down toward the lower right border. The title Dominus Noster ("Our Lord") reflects the standard late fourth-century titular prefix, combined with the traditional triumphal epithets Pius ("Dutiful" or "Pious") and Felix ("Fortunate"), terminating in the constitutional designation Augustus.

Selected Issues: Reverse: Iconographic Composition

The reverse composition depicts two imperial rulers seated side-by-side in full frontal orientation upon a wide, backless curule bench or subsellium. Both rulers wear identical imperial robes (chlamydes) draped across their shoulders and laps. Their outer arms rest symmetrically upon their thighs, while their inner arms are raised together to jointly support a central celestial globe (globus). This shared sphere signifies undivided dominion, universal authority, and joint stewardship over the Roman world.

Positioned centrally behind the two seated rulers is the standing winged figure of Victory (Victoria). Facing frontally, she spreads both wings outward in a wide protective arch, allowing each wing tip to hover over the head of an enthroned emperor. In the lower field, rising vertically from the groundline between the rulers' feet, stands a single palm frond, a classical emblem of enduring military triumph and divine favor. The entire tableau is enclosed within a fine outer beaded circle.

Selected Issues: Reverse: Epigraphy and Inscriptions

The reverse inscription is executed in monumental Latin capitals along the perimeter:

• Script: Latin capital script
• Language: Latin
• Verified Lettering: VICTOR-IA AVGG
• Transliteration / Expansion: Victoria Augustorum
• English Translation: "Victory of the [two] Augusti"

The legend runs along the upper circumference of the flan, interrupted at the top center above the head and outspread wings of Victory (VICTOR-IA). The doubling of the consonant G at the end of the imperial title (AVGG) marks the genitive plural of two reigning emperors, distinct from the triple G (AVGGG) employed when three Augusti were officially acknowledged in coinage inscriptions.

In the lower exergue below the horizontal groundline, the mint signature and workshop identifiers are struck:

• Verified Series Marks: TROBC, TROBS, and TROBT

These exergual marks combine administrative and metrological indicators:

• TR: Abbreviation for Treveris, designating the imperial mint situated at Augusta Treverorum.
• OB: Represents obryzum, certifying that the solidus was struck from chemically tested, refined gold. Simultaneously, the characters function as the Greek alphabetic numeral OB (Omikron = 70, Beta = 2), signifying the statutory weight standard of 72 solidi to the Roman pound.
• C, S, T: Workshop (officina) distinctions separating the three operating gold ateliers at Trier during Period III.

Typology and Documented Variants

The "Two Emperors Enthroned" solidus design at Augusta Treverorum spans three successive chronological phases across Gratian's Western rule:

Period II Antecedents (c. 367-375 CE)

Preceding the death of Valentinian I, solidi bearing the seated emperors were issued under RIC IX Treveri 17g (Depeyrot 43/3-4). These issues predominantly display a rosette-diademed bust of Gratian with reverse exergual formulas reading TROB, TROBS, TROBT, or TR•OB•, issued alongside parallel emissions struck for Valentinian I and Valens.

Period III Issues (c. 17 November 375 - 9 August 378 CE)

Following the death of Valentinian I, the seated emperors motif was maintained as the standard Western solidus type at Trier under RIC IX Treveri 39 (Depeyrot Emission 45). The series is classified into two major obverse styles and three officina subtypes:

1. Rosette-Diademed Series (RIC IX Treveri 39c; Cohen 38): Features a rosette-diademed, draped, and cuirassed bust facing right. Documented with exergual marks TROBC, TROBS, and TROBT.
2. Pearl-Diademed Series (RIC IX Treveri 39d; Depeyrot 45/2): Displays a pearl-diademed, draped, and cuirassed bust facing right, representing the dominant obverse variant of the period. This series is divided by officina marks:
   • Officina 1 (RIC IX Treveri 39d.1): Exergue reading TROBC.
   • Officina 2 (RIC IX Treveri 39d.2): Exergue reading TROBS.
   • Officina 3 (RIC IX Treveri 39d.3): Exergue reading TROBT.

Period IV Developments (c. Late 378-383 CE)

After the fall of Valens at Adrianople and the subsequent elevation of Theodosius I, the solidus type continued at Trier under RIC IX Treveri 49b. These later issues exhibit minor shifts in legend division (such as unbroken VICTORIA AVGG) and expanded exergual marks, including TROBS, COM, and TRPS.

Scholarly Debates and Attribution Limitations

Identification of the Enthroned Figures

Numismatists have long examined the intended identity of the two seated rulers depicted on the reverse:

• Gratian and Valens: The consensus among modern authorities, notably J. W. E. Pearce and J. P. C. Kent, maintains that the figures represent Gratian in the West and his uncle Valens in the East. Both figures are rendered at identical physical scale as fully mature rulers, and the legend specifically reads AVGG with two Gs rather than three. This composition emphasized collegiate balance between the established senior rulers following the unexpected accession of the child Valentinian II.
• Gratian and Valentinian II: Earlier nineteenth-century commentators, including Henry Cohen, identified the two figures as Gratian and his half-brother Valentinian II, reflecting the Western regional court. However, subsequent Trier solidi struck after 378 CE (such as RIC IX Treveri 49c) deliberately depict Valentinian II as a diminutive, smaller figure seated beside an adult Gratian, suggesting that the equal proportions of RIC 39 depict Gratian and Valens.

Epigraphic Interpretation of Workshop Mark C

The exergue mark TROBC presents an unresolved epigraphic problem:

• The Capitalis Hypothesis: Georges Depeyrot suggested that C represents Capitalis (or Capita), designating a central or headquarters officina alongside the standard Latin ordinals S (Secunda) and T (Tertia). However, the designation Capitalis is not attested in contemporary administrative texts, leaving this hypothesis an unconfirmed numismatic interpretation.
• Alternative Explanations: Earlier scholars considered whether C represented an altered rendering of the Greek numeral Gamma (indicating a third workshop), though this has been largely set aside because Western gold workshops at Trier systematically utilized Latin lettering. Pearce recommended treating C, S, and T simply as institutional workshop distinctions without imposing modern administrative assumptions onto the abbreviations.

References

1. The Roman Imperial Coinage. Vol. IX: Valentinian I - Theodosius I. pp. xi-xii, 13-21, nos. 17g, 39c-d, 49b
2. Online Coins of the Roman Empire: RIC IX Treveri 39D. Type record ric.9.tri.39D and subtypes 39D.1, 39D.2, 39D.3
3. Description historique des monnaies frappées sous l'Empire Romain, Tome VIII. pp. 129-130, nos. 36-39
4. Catalogue of Late Roman Coins in the Dumbarton Oaks Collection. pp. 8-10, 38-41
5. The 'Collegiate' Coinage of the Fourth and Fifth Centuries. Numismatica e Antichità Classiche 22 (1993), pp. 217-228
6. Les monnaies d'or de Constantin II à Zénon (337-491). pp. 52, 119-122, emissions 43-45