Augustus Orichalcum Dupondius

Monetary Reform and Denominational Role

The introduction of the Augustan dupondius formed an integral part of the comprehensive restructuring of Roman state coinage undertaken during the early principate. Prior to this reform, the late Roman Republic had witnessed intermittent and chaotic production of base-metal issues, often leaving Roman commerce dependent on worn Republican bronze fractions, foreign currency, or local provincial coinages. Augustus regularized this landscape by establishing a coherent quadri-metallic monetary system comprising gold (aureus), silver (denarius), brass or orichalcum (sestertius and dupondius), and pure copper (as, semis, and quadrans). In this hierarchy, the dupondius occupied a tariffed value of two copper asses, four quadrantes, or half an orichalcum sestertius, corresponding to one-eighth of a silver denarius. The deliberate choice to mint the dupondius in orichalcum, an artificial brass alloy containing approximately 15 to 25 percent zinc alongside copper, was central to the Augustan denominational scheme. Because orichalcum was prized for its golden luster and held an intrinsic monetary value approximately double that of pure red copper, a dupondius could be struck at roughly the same physical weight and module as the pure copper as (approximately 10.5 to 13.0 grams) while officially commanding twice the purchasing power.

Production, Metallurgy, and Mint Organization

Production of the Augustan dupondius occurred across several primary administrative nodes within the western empire. The mint at Rome served as the initial center for imperial brass emissions following the reform, producing substantial volumes between roughly 19 BC and the final decade BC under the supervision of senatorial magistrates. Striking in orichalcum required sophisticated metallurgical control, as zinc was introduced into copper through the cementation process using calamine ore (zinc carbonate) heated in crucibles. Chemical and spectroscopic analyses of early Augustan dupondii demonstrate a zinc content commonly between 16 and 22 percent, which provided the distinct bright yellow coloration essential for denomination recognition. Beyond the capital, secondary imperial production expanded dramatically to meet regional military and administrative demand. The imperial mint established at Lugdunum (modern Lyon, France) began striking bronze and brass currency around 15 BC, becoming the primary western source of dupondii by the end of Augustus's reign. Concurrently, major colonial and provincial mints, notably Nemausus (Nimes) in Gallia Narbonensis and various cities in Hispania such as Emerita Augusta, Caesaraugusta, and Bilbilis, struck extensive series of dupondii or local equivalents adhering to or approximating the imperial weight standard.

Obverse Iconography and Imperial Representation

The obverse typology of Augustan dupondii displays notable diversity across different minting authorities and chronological phases. At the mint of Rome, the earliest issues struck under the triumviri monetales often eschewed the princeps's portrait entirely, presenting instead anepigraphic civic motifs, civic laurels, an oak wreath (corona civica), or formal titular inscriptions enclosing sacrificial emblems or curule chairs. When imperial portraits appeared on subsequent Roman and provincial emissions, they introduced the classicizing Augustan portraiture crafted in the Julio-Claudian dynastic style, characterized by calm, idealized features, neatly parted comma-shaped locks of hair, and an ageless profile facing left or right. Notably, the Augustan dupondius did not yet utilize the radiate solar crown that became the standardized diagnostic attribute of the denomination under Nero in 64 AD. Augustus is predominantly depicted bareheaded or wearing a laurel wreath. On the prolific provincial dupondius series of Nemausus, the obverse bears the distinctive adossed, back-to-back portrait heads of Augustus, crowned with laurel, and Marcus Vipsanius Agrippa, wearing the rostral crown (corona navalis), signifying their joint civil and naval mastery over the Mediterranean world following the battle of Actium.

Reverse Typology and Ideological Messaging

The reverse designs of Augustan dupondii communicated key messages of political legitimization, administrative authority, and imperial victory. On Rome-minted moneyer issues, the reverse field is typically dominated by a monumental central legend, S C (Senatus Consulto, 'by decree of the Senate'), framed by an outer circular inscription recording the full name, patronymic, and magistracy of the individual moneyer. This composition underscored the constitutional fiction of senatorial oversight over base-metal currency while functioning under imperial sanction. At the Lugdunum mint, dupondii shared the famous 'Altar of Roma and Augustus' design with the contemporary as, depicting the ornate ceremonial altar dedicated at the confluence of the Rhone and Saone rivers in 10 BC. The altar structure is flanked by two Victories set atop columns, each holding a palm branch and wreath, while the altar face is decorated with reliefs depicting civic celebrations and sacrificial processions. At Nemausus, the reverse iconography presents a chained crocodile tethered to a palm tree surmounted by a wreath, with two palm branches hanging below, symbolically representing the conquest and annexation of Ptolemaic Egypt following the fall of Alexandria in 30 BC.

Epigraphy and Titulature

The epigraphic repertoire of the Augustan dupondius records the progressive accumulation and institutionalization of Augustus's official titles. On Roman moneyer dupondii, imperial inscriptions frequently feature AVGVSTVS TRIBVNIC POTEST or CAESAR AVGVSTVS PONT MAX TRIBVNIC POT, advertising his annual tribunician power (tribunicia potestas) and his election as Pontifex Maximus in 12 BC. The names and titles of the moneyers appear in full classical Latin formula, such as C GALLIVS C F LVPERCVS IIIVIR A A A F F, signifying 'Caius Gallius Lupercus, son of Caius, triumvir for casting and striking bronze, silver, and gold'. Lugdunum emissions consistently bear the reverse legend ROM ET AVG ('to Roma and Augustus') in the exergue beneath the altar, while the obverse titles emphasize his position as CAESAR AVGVSTVS DIVI F PATER PATRIAE ('Caesar Augustus, Son of the Divine, Father of the Country'). The colonial coinage of Nemausus records the abbreviated obverse legend IMP DIVI F ('Imperator, Son of the Divine') along with the reverse civic ethnic COL NEM (Colonia Nemausensis). Letters were executed in neat, disciplined lapidary capitals, reflecting the artistic revivalism of the Augustan age.

Typological Sequences and Chronological Phases

The chronology of the Augustan dupondius can be divided into three principal phases reflecting changing institutional practices. The first phase spans roughly 23 BC (or c. 19 BC according to alternative modern numismatic chronologies) to approximately 6 BC, during which the mint of Rome operated under the names of annual collegia of triumviri monetales. Scholars categorize these moneyers into successive compositional groups, beginning with anepigraphic portraitless series and culminating in portrait emissions carrying tribunician dating. The second phase, commencing around 10 to 7 BC and running into the final years of the principate, witnessed the cessation of moneyer signatures at Rome and the ascent of the imperial branch mint at Lugdunum. Lugdunum dupondii of the Altar series were issued in substantial volumes in two major chronological pulses: the first pulse around 10 to 7 BC, and a renewed second pulse between roughly 9 and 14 AD featuring Augustus's definitive title Pater Patriae. Parallel to these imperial lines, the third sequence comprises the provincial and colonial issues, exemplified by the four sequential stylistic groups of Nemausus struck from approximately 20 BC through the early decades of the first century AD, alongside the autonomous emissions of the Spanish colonies.

Circulation, Wear, and Halving

Augustan dupondii circulated extensively across the western and Danubian provinces of the empire, serving as indispensable everyday currency for civilian markets and military encampments. Archaeological excavations along the Rhine and Danube frontiers, notably at sites such as Haltern, Kalkriese, and Vindonissa, reveal massive concentrations of Augustan orichalcum pieces alongside copper asses. Because base-metal supply often lagged behind regional demand in newly annexed territories, Augustan dupondii remained in active circulation for decades, frequently surviving in circulation contexts well into the Flavian period. A widespread numismatic phenomenon documented in Augustan western contexts is intentional halving: dupondii, particularly the Nemausus series and Roman moneyer types, were deliberately cut in half by chisel to function as asses during acute shortages of small change. Over time, as circulation wore away the golden orichalcum surface and exposed a dull patina, public discrimination between worn dupondii and worn copper asses became increasingly difficult due to their overlapping physical dimensions. This practical ambiguity directly influenced later monetary reforms, ultimately prompting the Neronian introduction of the radiate crown as an explicit visual denomination marker for the dupondius.

References

1. Coins of the Roman Empire in the British Museum, Volume I: Augustus to Vitellius. pp. xcvi-cviii, 28-56
2. Roman Provincial Coinage, Volume I: From the Death of Caesar to the Death of Vitellius (44 BC-AD 69). pp. 152-155, 178-181
3. The Composition of Ancient Orichalcum (Brass). pp. 12-45
4. The Roman Imperial Coinage, Volume I: From 31 BC to AD 69 (Revised Edition). pp. 58-81
5. The Emperor and the Coinage: Julio-Claudian Studies. pp. 1-36