Nero Orichalcum Sestertius, RIC I (second edition) Nero 178

Monetary Context and the Neronian Currency Reform

The sestertius catalogued as RIC I (second edition) Nero 178 appeared as part of the thorough restructuring of the Roman monetary system undertaken during Nero's reign, traditionally dated to around 64 AD. Prior to this reform, the minting of base-metal coinage at Rome had been largely dormant since the reign of Claudius, leaving Western markets reliant on older Julio-Claudian issues and circulating provincial or auxiliary imitations. Nero restored base-metal production on a grand scale, introducing notable technical and metrological modifications. Under this reformed system, the sestertius continued as the premier denomination of regular base-metal exchange, tariffed at four asses or one-quarter of a silver denarius. Unlike the smaller asses and dupondii, which saw experimental and alternating uses of pure red copper and golden brass (orichalcum), the sestertius was consistently struck in orichalcum, an alloy of copper and zinc valued for its bright, brassy appearance and high perceived worth. The extensive broad flan of the sestertius, typically spanning between 34 and 37 millimeters, made it an ideal vehicle for complex pictorial compositions that carried explicit civic, military, and economic narratives. By deploying the newly re-engineered Ostian harbor design on this monumental denomination, imperial authorities emphasized the physical stability of Rome's daily sustenance and the restored administrative vigor of the imperial grain infrastructure.

Mint Organization, Metallurgy, and Die Cutting

RIC I (second edition) Nero 178 is securely assigned to the primary imperial mint at Rome. While Nero also established an active auxiliary mint for base metals at Lugdunum (modern Lyon) to supply the western provinces, the specific die characteristics, stylistic execution, and obverse epigraphy of type 178 align exclusively with the central metropolitan workshop. The flans for these sestertii were cast as heavy, thick blanks of orichalcum, usually adhering to an intended standard near 26 to 28 grams, though specimens display normal ancient weight variance across the wider range of approximately 24 to 30 grams. Striking these massive copper-alloy flans required tremendous mechanical force, likely executed using heavy iron two-man sledgehammers upon engraved lower (obverse) dies set into an anvil and upper (reverse) dies held in tongs. The die engraving of this issue represents a zenith of Julio-Claudian numismatic art. The die cutters at Rome achieved exceptional spatial depth on a low-relief metallic plane, utilizing multiple planes of perspective to render the curved moles, interior ships, and elevated architectural monuments of the harbor basin without descending into visual confusion. Small differences in the positioning of port structures and vessel counts reflect multiple hand-cut die pairings operating concurrently within the mint.

Obverse Iconography and Regal Presentation

The obverse of RIC 178 features a right-facing portrait of Nero wearing a laurel wreath, with an aegis draped upon his neck. In contrast to the juvenile and modest portrait styles characteristic of Nero's earliest coinage, issues of the reformed period display a mature, imposing, and muscular likeness with a heavy jawline, stylized neck folds, and carefully arranged tiers of hair brushed forward across the brow. The inclusion of the aegis, a divine attribute associated with Jupiter and Minerva, serves as a direct iconographic statement of divine protection and imperial sovereignty. The laurel wreath, tied at the nape of the neck with fluttering ribbon ends, reinforces his triumphs and civilian leadership. The entire portrait is enclosed by a continuous beaded border, against which the imperial titulature is struck in bold, classical Roman capital letters. Die engravers varied subtle aspects of the portrait modeling, but the specific combination of a rightward gaze, laurel wreath, and neck aegis remains the diagnostic criterion distinguishing this exact obverse variety from companion types that omit the aegis or feature a bare head or left-facing bust.

Reverse Iconography: The Harbor of Ostia

The reverse design of RIC 178 is an intricate topographical view of the Portus Augusti at Ostia, the artificial harbor complex constructed near the mouth of the Tiber. The composition is arranged in an aerial or bird's-eye perspective. At the upper center, marking the seaward entrance between the enclosing moles, stands a tall multi-tiered lighthouse (pharos) surmounted by a colossal statue of Neptune holding a scepter or trident. Flanking the entrance are the extending arms of the harbor: on the left, a curved jetty or breakwater lined with porticoed warehouses or berths ending in a small shrine, and on the right, an enclosing mole or breakwater of columns and mooring facilities. Within the sheltered basin created by these arms, varying numbers of vessels, typically ranging from three to eight depending on the die, are depicted at anchor, being rowed, or unloading cargo, detailing the vibrant commerce of the port. At the bottom of the field, below the basin and completing the frame, reclines a personification of the river god Tiber (Tiberis). The bearded deity faces left, resting his left arm on a water urn or holding a dolphin and rudder, with a reed held across his torso. This juxtaposition visually links the maritime trade brought into Ostia directly to its passage upriver into the heart of Rome.

Epigraphy and Inscriptional Formulas

The inscriptions on RIC 178 provide vital chronological, political, and institutional context for the issue. The obverse legend reads NERO CLAVD CAESAR AVG GER P M TR P IMP P P, expanding to 'Nero Claudius Caesar Augustus Germanicus, Pontifex Maximus, Tribunicia Potestate, Imperator, Pater Patriae'. This standard titulature declares his full adopted Claudian lineage, his supreme pontificate, his tribunician authority over the Roman people, his imperial military acclamations, and his accepted honorific of Father of the Fatherland. Notably, the tribunician number is omitted, a standard convention on Neronian base-metal issues from Rome that complicates strict annual dating. The reverse features two distinct epigraphic components. Encircling the upper perimeter of the design is the legend AVGVSTI S POR OST C, which is widely understood to expand as 'Augusti Senatus Consulto Portus Ostiensis' or 'Portus Ostiensis Senatus Consulto Augusti'. The letters S and C of the primary legend are divided across the field or integrated within the phrase, signifying 'Senatus Consulto' (by decree of the Senate), the traditional formula denoting senatorial authorization for the striking of token or base-metal coinage. The text explicitly brands the harbor complex as the work and gift of the emperor (Augusti), publicly celebrating the regime's successful completion of a perilous civil works program that had resisted earlier engineering attempts.

Typological Classification and Chronological Placement

In the standard classification of Roman Imperial Coinage, RIC I (second edition) Nero 178 is one of several closely related catalogued entries documenting the Ostia harbor series. While modern numismatic databases such as Online Coins of the Roman Empire record the theoretical envelope of Nero's reformed aes issues between 62 and 68 AD, modern research consensus generally places the active striking of this specific architectural type between approximately 64 and 66 AD. Claudius had initiated construction on the Ostian harbor basin in 42 AD to alleviate the dangerous silting and seasonal vulnerability of Rome's maritime logistics, but the grand works were brought to operational completion only under Nero, likely prompting this commemorative issue. Typologically, RIC 178 is separated from its immediate neighbors by precise obverse criteria: it bears the right-facing laureate portrait combined specifically with the aegis on the neck and the fully developed obverse legend ending in IMP P P. Other catalogued types in the series feature a left-facing bust, omit the aegis, show a bare head, or carry slight variants in the abbreviation of the harbor formula, such as PORT OST or PORTVS AVGVST. RIC 178 thus constitutes a distinct, tightly defined die grouping within the broader Ostia series.

Circulation, Economic Function, and Archeological Survival

As the highest denomination of everyday circulation, the sestertius fulfilled a dual economic and political purpose. In daily commerce, sestertii of the Neronian reform facilitated substantial market transactions, grain purchases, tax settlements, and military distributions. Archaeological findspots across Italy, Gaul, the Rhine frontier, and Britain demonstrate that Neronian orichalcum sestertii circulated widely throughout the Western empire for decades after his death, frequently remaining in active commercial pools until the Antonine and Severan periods, often heavily worn or countermarked under the Flavians. Because the Ostia sestertii combined high artistic merit with an intricate depiction of a famous public monument, specimens were also preserved in domestic hoards. Due to their complex, crowded reverse dies, surviving specimens exhibit considerable variation in wear, striking center, and planchet conservation. Specimens preserving full details of the harbor moles, tiny interior ships, and the reclining river god remain crucial primary documents for classical architectural historians and maritime archaeologists reconstructing the lost engineering works of the Julio-Claudian era.

References

1. Coinage in the Roman World. pages 86-98
2. Coins of the Roman Empire in the British Museum, Volume I: Augustus to Vitellius. pages 221-224
3. Online Coins of the Roman Empire: RIC I (second edition) Nero 178. ric.1(2).ner.178
4. The Roman Imperial Coinage, Volume I: From 31 BC to AD 69 (revised edition). pages 130-160, no. 178