Trajan Orichalcum Sestertius RIC II Trajan 631

Monetary Context and Imperial Function

During the High Empire, the sestertius served as the flagship denomination of the base-metal monetary system. Formed of orichalcum, a golden-toned copper alloy rich in zinc, the sestertius carried an official tariff of four copper asses, two brass dupondii, or one-fourth of a silver denarius. Because of its substantial diameter and flan weight, typically averaging between 24 and 28 grams during Trajan's principate, the sestertius offered the die cutters of the Rome mint an expansive circular field unequaled by any contemporary precious-metal denomination. This expansive surface made the sestertius the preferred medium for complex architectural, institutional, and allegorical compositions that communicated state policy to the general public. In the early second century AD, the security of the annona, the vital grain supply feeding the metropolitan population of Rome, was a paramount concern of imperial governance. Claudius had initiated the first major artificial seaport north of Ostia, but the open outer basin remained vulnerable to severe maritime storms, as demonstrated by the catastrophic destruction of nearly two hundred grain ships during a single squall in AD 62. Trajan resolved this long-standing vulnerability through an ambitious engineering project: excavating an enormous hexagonal inner basin connected directly to the Claudian harbor and linked to the Tiber River via navigable canals. The emission of RIC II Trajan 631 was an ideological statement celebrating the completion of this monumental public work. By placing the newly operational Portum Traiani upon the most widely handled large-format denomination, the imperial administration reassured the citizenry of Rome and the wider commercial community across the Mediterranean that imperial logistics were secure against nature and famine.

Mint Organization and Production Technology

All specimens of RIC II Trajan 631 were manufactured at the central imperial mint in Rome, which maintained exclusive authority over the striking of senatorial bronze and brass denominations for western circulation. The production of orichalcum flans required sophisticated pyrotechnological management to maintain consistent ratios of copper and calamine zinc ore, producing the bright golden appearance prized in newly minted sestertii. Blanks were cast in individual molds or stepped flan sheets before being trimmed and heated to soften the alloy prior to striking. The mechanical operation involved an anvil die fixed within an oak block and a mobile reverse punch driven by heavy manual sledge blows. The striking of sestertii demanded significant physical impact to force the heated alloy into the deeply engraved cavities of the reverse die, which featured multi-layered relief ranging from the surrounding portico structures to the delicate hulls and masts of the vessels floating in the inner harbor. The die axes for this type conform closely to the standard regular alignment of the Roman mint during this period, predominantly striking at six o'clock or twelve o'clock. Production volumes for architectural commemorations under Trajan were substantial, yet the structural complexity of the reverse die led to frequent fracturing and progressive wear. Minor stylistic differences in die cutting reveal that multiple master engravers prepared dies for this series, occasionally varying the spacing of the architectural perimeter, the perspective tilt of the hexagonal basin, and the exact count or orientation of the small ships depicted inside the harbor.

Obverse Typology and Imperial Iconography

The obverse of RIC II Trajan 631 bears the right-facing, mature portrait of Trajan crowned with a laurel wreath, whose ties fall naturally along the nape of his neck. The portraiture belongs to the emperor's decennalia and post-decennalia stylistic phases, characterized by austere, heroic realism. The planes of the face are modeled with pronounced bone structure: a firm, square jaw, a prominent aquiline nose, closely cropped hair brushed forward in straight strands over a broad forehead, and a determined, tightly set mouth. This physiognomy deliberately broke with the soft, classicizing effigies of the Julio-Claudian dynasty and the fleshy exuberance of Domitian, projecting instead the traditional virtues of the military soldier-emperor devoted to discipline and civil duty. Die variations within the series exhibit subtle modifications in bust truncation. While the primary catalogue definition features a bare neck truncation ending cleanly above the legend line, some contemporary dies introduce subtle drapery on the far left shoulder, or occasionally present the emperor with drapery and a decorative cuirass visible at the edge of the shoulder. The laurel wreath symbolizes ongoing military triumph and imperial authority, rendered with tightly clustered pairs of laurel leaves secured by a central ribbon. The positioning of the bust is carefully proportioned within the circular field, leaving sufficient perimeter margins to accommodate the lengthy titulature without crowding the imperial features.

Reverse Iconography: The Hexagonal Basin of Portus

The reverse of RIC II Trajan 631 presents an extraordinary bird's-eye perspective of the newly excavated Portus Traiani, providing one of the most celebrated topographical representations in ancient numismatic art. The composition is organized around a distinct, enclosed hexagonal water basin. Enclosing this hexagonal expanse is a continuous ring of architecture representing the extensive facilities of the port complex: multi-story warehouse blocks (horrea), arcaded colonnades, and administrative buildings where harbor officials, customs agents, and grain weighers conducted daily operations. At the entrance to the basin, typically oriented at the bottom or lower flank of the flan, the die carver depicted a monumental gateway or entrance mole flanked by statues, often interpreted from archaeological remains as colossi or lighthouses signaling the channel opening to approaching mariners. Within the basin itself, the calm water surface is populated by three to four small merchant ships, complete with visible hulls, oars, and riggings, illustrating the secure berthing provided by the enclosed design. This artistic perspective deliberately combines ground-level elevation for the perimeter buildings with a steep isometric overhead view of the harbor floor, enabling viewers to grasp both the monumental perimeter architecture and the functional interior basin simultaneously. In the lower field or flanking the design, the abbreviation S C signifies Senatus Consulto, declaring senatorial approval for the base-metal issue, while the surrounding inscription identifies the subject as the harbor of Trajan.

Epigraphic Analysis and Legend Interpretation

The legends on RIC II Trajan 631 are rendered in classical Roman epigraphic capitals, engraved with sharp serifs and consistent lettering heights. The obverse inscription reads continuously clockwise along the outer perimeter: IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS VI P P. Expanding the conventional abbreviations yields Imperatori Caesari Nervae Traiano Augusto Germanico Dacico, Pontifici Maximo, Tribunicia Potestate, Consuli Sextum, Patri Patriae. This epigraphic sequence conveys Trajan's full formal authority. It begins with his imperial praenomen and lineage, acknowledging his adoption by Nerva, followed by the honorific Augustus. The military cognomina Germanicus (awarded in AD 97) and Dacicus (awarded in AD 102) celebrate his frontier campaigns on the Rhine and Danube. His domestic magistracies follow: Pontifex Maximus denoting supreme religious primacy, Tribunicia Potestate signifying the inviolable civil authority of the tribunate, Consul Sextum recording his sixth consulship entered on January 1, AD 112, and Pater Patriae naming him Father of his Country. On the reverse, the primary inscription reads PORTVM TRAIANI, written in the accusative case (Portum Traiani), which grammatically references an understood verb such as fecit, perfecit, or dicavit, signifying that the emperor made or dedicated the harbor of Trajan. The presence of S C across the lower reverse field abbreviates Senatus Consulto, the traditional formula signifying that the brass coinage was produced under the formal constitutional authority of the Roman Senate.

Typological Sequences and Dating Criteria

The chronology of RIC II Trajan 631 is established through strict epigraphic boundaries present within Trajan's coinage. The obverse legend specifies COS VI, dating the striking to no earlier than January 1, AD 112, the date Trajan entered his sixth and final consulship. Conversely, the inscription omits the supreme imperial title OPTIMO AVG (or OPTIMVS), which was officially bestowed upon the emperor by the Senate in late summer or autumn of AD 114. Coinage produced after autumn AD 114 invariably incorporates Optimus into the obverse legend or reverse titulature, placing the production of RIC II Trajan 631 securely within the window of AD 112 to mid-114. In Bernhard Woytek's comprehensive corpus Die Reichsprägung des Kaisers Traianus (MIR 14), this issue is classified under group 423, situated among the celebratory emissions that commemorated the emperor's magnificent civil infrastructure projects in Italy alongside the Forum of Trajan, the Aqua Traiana, and the Via Traiana. RIC II Trajan 631 must be distinguished from the smaller and exceedingly rare dupondius emissions bearing a similar harbor reverse, as well as later hybrid varieties or post-114 re-issues where the title Optimus appears. Die studies confirm that several obverse dies utilized for RIC 631 were also coupled with alternative reverse types struck during the same emission period, including types featuring the Forum Traiani and the personification of Arabia, demonstrating concurrent operation of multiple workshops within the Rome mint.

Circulation Patterns, Wear, and Archaeological Recovery

As high-value base-metal pieces, orichalcum sestertii occupied an active position in daily urban commerce, operating at the threshold between daily retail transactions and larger market payments. Sestertii regularly circulated across the Italian peninsula and the western provinces, including Gaul, Hispania, Britain, and along the Rhine-Danube military frontier. While small bronze quadrantes and asses moved within localized municipal markets, sestertii traveled across wider regional trade networks. Surviving specimens of RIC II Trajan 631 demonstrate variable patterns of commercial wear, with many exhibiting softened architectural details resulting from decades of circulation through the second and early third centuries AD. Because sestertii were not hoarded as aggressively as silver denarii or gold aurei, individual specimens are predominantly recovered from urban archaeological deposits, harbor dredging operations, river beds, and mixed base-metal hoards buried during times of economic distress. The distinctive harbor design made the coin readily identifiable even in antiquity, and contemporary hoard evidence confirms that Trajanic sestertii remained in active circulation well into the Severan era, often remaining in use until the monetary reforms and debasements of the mid-third century AD diminished the purchasing power of classical orichalcum denominations.

References

1. The Roman Imperial Coinage, Vol. II: Vespasian to Hadrian. pp. 288-289, no. 631
2. Online Coins of the Roman Empire: RIC II Trajan 631. RIC II Trajan 631
3. Untersuchungen zur römischen Reichsprägung des zweiten Jahrhunderts, Teil I: Die Reichsprägung zur Zeit des Traian. pp. 195-202
4. Die Reichsprägung des Kaisers Traianus (98-117) (Moneta Imperii Romani 14). no. 423