Trajan Orichalcum Sestertius, RIC II Trajan 632

Monetary Context and Denominational Function

During the reign of Trajan, the sestertius held a premier position within the Roman monetary system. Valued at one-fourth of a silver denarius or four copper asses, the sestertius was the largest regular base-metal coin struck in the Roman world. Traditionally cast and struck in orichalcum, a golden-toned copper-zinc brass alloy, it commanded a notable physical presence in daily transactions. Beyond its routine domestic utility for purchasing high-volume staples, paying rent, and conducting provincial trade, the broad flan of the sestertius made it the premier vehicle for official state messaging and public relations. Trajan capitalized on the large surface area of the sestertius to advertise his military victories in Dacia, public infrastructure initiatives, and extensive civic benefactions. The issue of RIC II Trajan 632 occurred against the backdrop of immense fiscal liquidity generated by the Dacian spoils, which funded ambitious building programs across Rome and Italy. At this time, maritime logistics constituted an existential concern for the Roman administration, as the capital depended entirely on sea-borne grain shipments from Egypt, North Africa, and Sicily. Claudius had earlier constructed an outer basin at Ostia, but severe storms and progressive silting left maritime transport vulnerable. Trajan addressed this vulnerability by excavating a colossal, sheltered hexagonal basin further inland, linked by canals to the Tiber River. Struck between AD 112 and 114, RIC II Trajan 632 was released into circulation to announce the operational success of this logistical triumph to the Roman populace.

Production, Minting, and Physical Standards

RIC II Trajan 632 was produced exclusively at the imperial mint in the city of Rome, which monopolized base-metal coinage struck for Italy and the western provinces. The manufacture of orichalcum sestertii required sophisticated pyrotechnic and metallurgical mastery. The alloy was produced primarily through the cementation process, wherein granulated copper was heated with calamine (zinc carbonate ore) and charcoal in sealed crucibles, yielding a distinctive brass with approximately fifteen to twenty percent zinc content, though proportions varied across production batches. Individual blank flans were cast, typically in open or bivalve molds, before being heated and adjusted mechanically. The physical standards of Trajanic sestertii in this period adhered to a nominal target weight centering between 25 and 28 grams, with diameters commonly spanning 33 to 36 millimeters, although broad tolerances were customary in ancient token coinage. Dies were aligned along a standard Roman imperial twelve o'clock or six o'clock axis, with slight rotational shifts common in manual striking. The intricate architectural reverse required masterful die engraving. Celators cut miniature representations of columned colonnades, pedimented warehouses, maritime structures, and diminutive sailing vessels directly into intaglio bronze or iron dies. The striking process demanded substantial physical force, often requiring several hammer blows while the flan was red-hot to force metal into the high-relief details of Trajan's portrait and the intricate hexagonal basin.

Obverse Portraiture and Style

The obverse of RIC II Trajan 632 features a right-facing bust of Trajan that exemplifies the dignified, realistic style of his mature principate. In this specific catalogue entry, the emperor is depicted with a laurel wreath bound behind the head with ribbons that descend onto the nape of the neck, accompanied by drapery gathered at the shoulder. Trajan's hair is rendered in the signature early imperial brush style, cut straight across the low forehead, recalling the sober Augustan aesthetic rather than the elaborate coiffures of the Flavian era. The facial features convey gravitas, characterized by a firm jaw, a prominent aquiline nose, pronounced nasolabial folds, and deep-set eyes that project authority, discipline, and sobriety. The drapery visible over his far shoulder provides balance to the composition, while the laurel wreath symbolizes triumphant military and civil leadership. The portrait occupies the central field of the flan, framed neatly by a continuous circumferential inscription that starts in the lower left field and terminates in the lower right, bordered externally by a raised beaded rim. The engraving exhibits the high technical artistry of the primary Rome mint ateliers during the second decade of the second century AD, capturing personal physiognomy while conveying an idealized aura of imperial stability.

Reverse Iconography: The Hexagonal Harbor of Portus

The reverse design of RIC II Trajan 632 presents an architectural view of the inner harbor basin at Portus, known as the Portus Traiani. Rendered in a conventional combined perspective that merges an aerial plan with low-angle elevation views, the design depicts the basin as a regular hexagon. Each of the six sides of the perimeter is demarcated by colonnaded porticoes, open dock fronts, and multi-story warehouses (horrea) indicated by tiny arcades and structural divisions. Architectural features dot the perimeter, including pedimented storehouses, an entrance canal flanked by piers or beacon towers, and mooring facilities. Within the hollow center of the basin, the celator engraved three distinct transport vessels floating on the water. These merchant vessels, depicted with detailed hulls, small superstructures, and masts, symbolize the active commercial fleet unloading maritime freight into imperial storehouses. In the exergue or divided fields beneath the basin, the legend PORTVM TRAIANI appears, accompanied by the standard senatorial authorization mark S C (Senatus Consulto). This reverse is among the most celebrated topographical representations in ancient numismatics, functioning as a visual document of Roman civil engineering that directly mirrors archaeological remains excavated at modern Fiumicino.

Epigraphy and Titulature

The inscriptions on RIC II Trajan 632 present complete epigraphic formulas that precisely date the issue and establish Trajan's constitutional authority. The obverse legend reads IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS VI P P, rendered in the dative case (Imp[eratori] Caes[ari] Nervae Traiano Aug[usto] Ger[manico] Dac[ico] P[ontifici] M[aximo] Tr[ibunicia] P[otestate] Co[n]s[uli] VI P[atri] P[atriae]). This dative construction reflects the Senate and the Roman people dedicating the coinage in honor of the emperor. The title Imperator Caesar identifies his supreme military command and imperial lineage from his adoptive father, the deified Nerva. The agnomina Germanicus and Dacicus commemorate his successful campaigns along the Rhine and the conquest of Dacia. The offices of Pontifex Maximus and Pater Patriae record his supreme religious oversight and status as father of his country. The inclusion of COS VI establishes that Trajan had entered his sixth consulship, an office he assumed on January 1, AD 112. The reverse inscription reads PORTVM TRAIANI, written in the accusative case (Portum Traiani), directly identifying Trajan's harbor as the subject of the monument. In the exergue or flanking the harbor basin, the letters S C (Senatus Consulto, 'by decree of the Senate') confirm the formal senatorial authorization standard on imperial base-metal denominations struck at Rome.

Typology and Chronological Classification

Within Trajan's extensive coinage, the harbor sestertii represent a tightly circumscribed typological group. In the standard system of The Roman Imperial Coinage (RIC), this specific variety is designated as RIC II Trajan 632, distinguished by Trajan's obverse bust showing drapery in addition to the laurel wreath. Bernhard Woytek, in his comprehensive modern corpus Die Reichsprägung des Kaisers Traianus (MIR 14), places the harbor type under issue group MIR 14, 471, subdividing the series according to bust treatments: bare neck with laurel wreath, draped bust, or draped and cuirassed bust. The chronological bracket for RIC II Trajan 632 is securely anchored between AD 112 and 114. The terminus post quem of AD 112 is established by the title COS VI, which Trajan assumed at the start of that year. The terminus ante quem of late AD 114 is provided by the absence of the title Optimus, which was formally bestowed upon Trajan by the Senate in autumn AD 114 and immediately incorporated into subsequent coin legends. Although archaeological and epigraphic evidence indicates that excavation and construction of the hexagonal basin began earlier in the decade, the appearance of the coin type between AD 112 and 114 marks the formal dedication or official commissioning of the completed facility.

Circulation Patterns and Archaeological Context

As an official brass sestertius, RIC II Trajan 632 circulated extensively across the Roman Empire, although find distributions reflect a heavy concentration in Italy, Gaul, and the western provinces where base-metal denominations formed the daily lifeblood of market economies. Sestertii had a long functional lifespan, often remaining in active circulation for decades. Many specimens of the harbor type exhibit moderate to heavy surface abrasion, attesting to continuous circulation alongside sestertii of the subsequent Antonine emperors until the debasements and monetary reforms of the mid-third century AD gradually drove large early orichalcum pieces out of the commercial pool. Hoard evidence from Italy and the northern frontiers shows that Trajanic sestertii circulated alongside both earlier Flavian and later Hadrianic issues. Due to the high aesthetic and thematic appeal of the Portus Traiani design, specimens of RIC II Trajan 632 were also noted and studied by early modern antiquarians, frequently appearing in major European cabinet collections formed from Italian river dredgings and urban excavations around Rome and Ostia. Archaeological discoveries at the Portus site itself have confirmed the structural layout captured so precisely by the die cutters who produced this issue.

References

1. The Roman Imperial Coinage, Vol. II: Vespasian to Hadrian. p. 289, no. 632
2. Online Coins of the Roman Empire: RIC II Trajan 632. ric.2.tr.632
3. Untersuchungen zur römischen Reichsprägung des zweiten Jahrhunderts, Teil I: Die Reichsprägung zur Zeit des Traian. p. 209, no. 436
4. Die Reichsprägung des Kaisers Traianus (98-117) (MIR 14). MIR 14, 471f