Trajan Copper-Alloy Dupondius

Monetary Context and Denominational Function

In the reformed monetary system established by Augustus and continued through the High Empire, the dupondius represented a value of two asses, four quadrantes, or half a sestertius, with four dupondii equivalent to one silver denarius. While the sestertius served as the primary large brass denomination for high-value public messaging and the copper as functioned as the workhorse for everyday petty transactions, the dupondius bridged these two strata, facilitating daily urban commerce and market change throughout the Roman Mediterranean. Trajan inherited this stable denominational matrix in 98 AD and maintained its traditional alloy and weight relationships throughout his nineteen-year reign. The dupondius occupied a distinctive technical position because it was manufactured from orichalcum, an alloy of copper and zinc known to the Romans for its bright, brassy appearance that initially resembled gold. Because an orichalcum dupondius was close in physical diameter and mass to the red-copper as, Roman mint authorities maintained the iconographic convention established under Nero: the dupondius featured a radiate portrait of the emperor, while the as featured a laureate head. This denominational convention ensured that users could instantly differentiate the two denominations even when circulation wear, patination, or ground corrosion obscured the original metallic color.

Mints, Metallurgy, and Physical Standards

The overwhelming majority of Trajan's imperial dupondii were struck at the single official imperial mint operating in the city of Rome. Although some eastern provincial mints produced local bronze denominations and occasionally struck Latin-legend brass pieces for regional circulation in Syria or Cyrenaica, the standard imperial dupondius carrying the senatorial formula S C was an urban Roman product. Metallurgically, Trajanic dupondii were cast as circular flans from orichalcum before striking. Analyses of contemporary Trajanic brass reveal a zinc content typically ranging between 12 and 18 percent, down slightly from the highest proportions seen in the Augustan and Claudian periods due to the progressive recycling of scrap brass. Physical standards for Trajan's dupondius reflect a targeted theoretical weight centered around 12 to 14 grams, with median flan diameters measuring between 26 and 28 millimeters. Striking was performed with fixed die axes, overwhelmingly favoring regular vertical alignments of 6 o'clock or 12 o'clock, characteristic of the disciplined operational structure of the Roman mint under its procurator monetae.

Obverse Portraiture and Iconography

The obverse of the Trajanic dupondius is universally defined by the radiate crown, the spikes of which symbolize solar radiance and served as the absolute numismatic marker of the denomination. Trajan is presented in right-facing or, less frequently, left-facing bust types, depicted in varied dress reflecting his dual civil and military personae. Early issues of 98 to 102 AD present a relatively restrained, veristic portrait style continuing the realistic Flavian and Nervan traditions, featuring prominent facial features, a straight nose, and combed-forward hair cut in a clean fringe across the forehead. As Trajan's reign progressed and his military triumphs accumulated, the imperial portraiture assumed a broader, more idealized heroic character. The bust is frequently shown draped, cuirassed, or bare-necked with light drapery on the left shoulder. Engravers at the Rome mint captured the emperor's aging profile while conveying steady imperatorial majesty, creating an authoritative iconography that endured as a visual standard for the remainder of the Antonine era.

Reverse Iconography and State Themes

Trajan used the reverse fields of his dupondii to disseminate the extensive political, military, and infrastructural programs of his principate. A substantial segment of the coinage commemorated the Dacian Wars of 101 to 102 AD and 105 to 106 AD. These types depict trophies of arms, mourning personifications of Dacia seated upon shields, captive Dacians standing with bound hands, and Victoria inscribing shields or erecting war trophies. Following the annexation of the Nabataean kingdom, dupondii celebrated Arabia Adquisita, personified standing with a camel and a bundle of frankincense. Beyond foreign conquest, civic and religious themes abounded. Reverse types regularly depicted traditional Roman virtues, including Pax holding an olive branch and cornucopiae, Felicitas with caduceus and cornucopiae, Annona dispensing grain, and Fortuna holding a rudder and cornucopiae. Trajan also commemorated his extensive public works and monumental architecture, displaying depictions of the Danube bridge engineered by Apollodorus of Damascus, the Forum of Trajan, the Basilica Ulpia, and the monumental Column of Trajan, rendering the dupondius a versatile medium of imperial propaganda.

Inscriptions and Epigraphic Formulas

The legends on Trajan's dupondii follow strict epigraphic conventions, recording his evolving offices and imperial titles. Obverse legends in the early reign typically open with IMP CAES NERVA TRAIAN AVG GERM, adding DACICVS following his victory in the First Dacian War in late 102 AD. In 114 AD, the Senate conferred upon him the unique honorific title Optimus, prompting the introduction of the obverse formula IMP CAES NER TRAIANO OPTIMO AVG GER DAC. Following the eastern campaigns against Parthia in 116 AD, the title PARTHICVS was integrated into the imperial nomenclature. Reverse inscriptions frequently continue the imperial titulature or proclaim specific achievements. Standard formulas include PONTIF MAX TR POT COS II, COS III, COS IIII, COS V, and COS VI, documenting his renewals of the tribunician power and consular elections. Triumphal phrases such as DACIA AVGVST PROVINCIA, ARABIA ADQVISITA, ALIM ITAL (celebrating the alimenta child welfare endowments), and SENATVS POPVLVSQVE ROMANVS explicitly interpret the reverse scenes. Almost all regular imperial issues display the large letters S C in the field or exergue, affirming that the copper-alloy coinage was minted under the formal decree of the Senate.

Typology and Chronological Classification

Numismatists divide the dupondii of Trajan into distinct chronological phases keyed to his iterations of the consulship and triumphal cognomina. Phase 1 spans 98 to 100 AD (Consulships II and III), characterized by the adoption of Nervan titles and standard personifications of peace and abundance. Phase 2 covers 101 to 102 AD (Consulship IV), dominated by preparations and initial engagements in Dacia. Phase 3 extends from 103 to 111 AD, an extensive period under Consulship V wherein Trajan bears the title Dacicus; this phase saw massive production of triumphal Dacian types, public works allegories, and the celebration of imperial infrastructure. Phase 4 begins in 112 AD with Trajan entering his sixth consulship (COS VI), which remained unchanged until his death. Within Phase 4, the introduction of OPTIMO in 114 AD and PARTHICO in 116 AD marks precise subdivisions. Bernhard Woytek's standard corpus (MIR 14) refined this sequence by correlating die linkages, stylistic changes in portraiture, and administrative reorganizations within the mint of Rome, superseding older broad groupings in early volumes of Roman Imperial Coinage.

Circulation, Hoards, and Archaeological Context

Trajan's dupondii circulated heavily throughout the western provinces of the empire, including Italia, Gallia, Britannia, the Germaniae, and the Danubian provinces. In contrast, the eastern Mediterranean provinces relied primarily on local civic bronze coinages and provincial tetradrachms, meaning imperial dupondii reached the Levant and Asia Minor mainly through military units and Roman administrative personnel. Archaeological excavation of military camps along the Rhine and Danube limites reveals dense concentrations of Trajanic dupondii and asses, which were distributed directly to legionaries and auxiliaries to fulfill military payrolls and maintain garrison economies. Because orichalcum and copper coinage circulated for decades without immediate recall, Trajan's dupondii remained in active circulation throughout the Antonine and Severan eras. Site finds and stray losses commonly show advanced states of wear, smoothing, and occasional countermarking. Hoard evidence demonstrates that while base-metal dupondii were less frequently hoarded than silver denarii or gold aurei, commercial bronze deposits from the second and third centuries AD regularly include Trajanic dupondii alongside sestertii.

References

1. Coins of the Roman Empire in the British Museum, Vol. III: Nerva to Hadrian. Trajan, pp. 148-232
2. The Roman Imperial Coinage, Vol. II: Vespasian to Hadrian. Trajan, pp. 273-298
3. Untersuchungen zur römischen Reichsprägung des zweiten Jahrhunderts, Teil I: Die Reichsprägung zur Zeit des Traian. Stuttgart 1931
4. Arma et Nummi: Forschungen zum Ausmünzungswesen des Kaisers Traian (MIR 14). Moneta Imperii Romani 14, Wien 2010