Nero Sestertius, RIC I (second edition) Nero 588

Monetary Context and the Neronian Currency Reform

The introduction of the Ostia harbor sestertius took place against the backdrop of Nero's sweeping transformation of the Roman monetary system, initiated around AD 64. Before this period, the Julio-Claudian dynasty had maintained a relatively conservative monetary structure established under Augustus, wherein the sestertius and dupondius were manufactured from bright orichalcum (a copper-zinc brass alloy), while the as, semis, and quadrans were produced in unalloyed red copper. Nero departed radically from this tradition by experimenting with orichalcum across all base-metal denominations, although public resistance and practical difficulties soon prompted adjustments. The sestertius, valued at four bronze asses or one-quarter of a silver denarius, represented the highest denomination in regular base-metal production. Because of its large module and substantial flan, it functioned as the primary vehicle for high-impact state propaganda, allowing the imperial administration to broadcast major civic triumphs, architectural achievements, and social policies to a wide audience across the empire. The Ostia type in particular addressed the delicate subject of grain supply security (cura annonae). Following serious food shortages and fires that had troubled Rome earlier in the century, the completion and expansion of harbor works begun under Claudius was of urgent domestic concern. By depicting the sheltered basin filled with maritime commerce, the imperial mint reassured the populace of Rome and the provincial armies that grain distribution remained safe, abundant, and under firm imperial oversight.

Production and the Lugdunum Mint Attribution

While Nero's earliest coinage was struck exclusively at the capital, the imperial government reopened regular base-metal operations at Lugdunum (modern Lyon) around AD 64 or 65 to supply the substantial currency requirements of Gaul, the German frontier legions, and Britain. Numismatic scholarship has long recognized that Lugdunum operated alongside Rome as a primary mint for aes issues during the last four years of Nero's reign. The attribution of RIC 588 to Lugdunum is supported by clear stylistic and technical markers identified by numismatists including C. H. V. Sutherland and D. W. MacDowall. Chief among these is the presence of a small globe or sphere positioned at the truncated point of the emperor's neck, an iconographic feature virtually universal to Western provincial die engraving under Nero. In addition, the Lugdunum mint exhibits a distinct engraving style: lettering is somewhat broader and more widely spaced, portrait relief tends to be slightly flatter yet meticulously modeled, and flan preparation demonstrates consistent weight control. The flans for these sestertii were cast in open or two-part molds before hot-striking between deeply carved bronze or iron dies. The survival of multiple reverse die varieties indicates a vigorous, high-volume production sequence carried out over several years, serving both military payroll needs along the Rhine limes and commercial trade along the Rhone-Saone river corridors.

Obverse Iconography and Imperial Portraiture

The obverse of RIC 588 displays a right-facing, laureate head of Nero. The portraiture belongs to the emperor's mature iconographic style, reflecting the heavy, fleshy features and elaborate coiffure that characterized his late coinage after AD 64. The hair is arranged in stepped, curling locks that cascade down the nape of the neck, a style frequently compared to the theatrical and athletic fashions favored by Nero himself. The laurel wreath rests upon the brow, tied at the back with ribbon tails (taeniae) falling over the neck. Below the truncation of the neck sits the small, neatly rendered globe, which acts as the definitive mint signature for the Lugdunum workshops. In Roman imperial ideology, the globe symbolized universal dominion and the cosmic order of the Roman world, but its specific placement at the tip of the neck on Julio-Claudian bronze was an administrative device designating mint organization. The artistic execution on Lugdunum dies combines formal imperial majesty with realistic, expressive portraiture, showing the thick neck, prominent chin, and deep-set eyes that distinguish Nero from his predecessors.

Reverse Design: The Harbor of Ostia

The reverse of RIC 588 is widely considered one of the masterpieces of Roman architectural numismatics. It presents a bird's-eye perspective of the harbor of Ostia, the artificial port constructed on the Tyrrhenian coast to bypass the silting mouth of the river Tiber. At the upper entrance of the harbor basin stands a multi-tiered pharos (lighthouse) surmounted by a colossal statue of Neptune, holding a trident. Below, framing the enclosed water basin, curved breakwaters or piers extend outward from either side: the left arm is lined with port buildings, warehouses, and an arcade or colonnade, while the right arm terminates in a breakwater or row of mooring slips. Within the safe interior waters, seven or eight merchant ships and galleys are depicted in various states of activity, some moored at quays and others actively under oar or sail, illustrating the vibrant commerce of the port. At the lower edge, reclined horizontally across the exergue, is the personification of the river god Tiber, depicted half-draped, facing left, holding a rudder or oar in one hand and a dolphin or marine attribute in the other. This dynamic composition successfully compresses a vast civil engineering project into a circular flan measuring barely thirty-five millimeters across, communicating imperial control over both maritime trade and terrestrial rivers.

Epigraphy and Legends

The obverse legend on RIC 588 reads continuously around the portrait: IMP NERO CAESAR AVG P MAX TR POT P P. Transcribed as Imperator Nero Caesar Augustus, Pontifex Maximus, Tribunicia Potestate, Pater Patriae, this sequence presents the full array of Nero's constitutional and religious authorities. The inclusion of the military title Imperator as a praenomen (forename) became standard on western aes issues from AD 66 onward, signifying the emperor's supreme command of the armed forces. The reverse legend is noticeably concise compared to earlier Roman issues of the harbor type. It reads PORT AVG across the field or upper periphery, accompanied by S C in the lower field or flanking the design. PORT AVG abbreviates Portus Augusti, or the 'Port of Augustus,' a title used here to associate Nero with the Augustan mantle of safety and peace, while directly commemorating the completed port facilities. The letters S C stand for Senatus Consulto, meaning 'by decree of the Senate.' This formulaic phrase was standard on imperial copper and brass coins, reflecting the traditional constitutional fiction that base-metal coinage was authorized under senatorial sanction, even when produced at provincial facilities such as Lugdunum.

Typology and Chronological Classification

In the standard classification of Roman Imperial Coinage, the Ostia harbor sestertii form a discrete series struck between AD 64 and AD 68 across multiple mints. RIC 588 is catalogued under the Lugdunum mint and is chronologically assigned to approximately AD 65 through 67, coinciding with the later phases of Nero's consolidated western coin production. It is distinguished from closely related Rome mint counterparts (such as RIC 178 through 183) by the globe on the obverse neck truncation, the specific arrangement of the obverse legend starting with IMP, and the simplified reverse inscription reading PORT AVG rather than the expanded PORTVS AVGVSTI or AVGVST S C POR OST found on Rome dies. Within the Lugdunum production itself, minor variants exist in the number of ships visible within the harbor basin, ranging from seven to eight vessels, as well as minor differences in the internal division of the reverse legend. Die studies conducted by MacDowall and other specialists demonstrate that these variations represent die-engraver idiosyncrasies rather than separate administrative emissions, belonging to a unified, sequential striking program.

Circulation, Hoards, and Archaeological Context

Sestertii of the Ostia type, including RIC 588, circulated heavily throughout the western provinces of the Roman Empire. Archaeological evidence from coin hoards and site finds confirms that Lugdunum-struck aes traveled rapidly northward and eastward from the mint along primary river corridors, supplying civilian markets and military garrisons in Gallia Lugdunensis, Gallia Belgica, Germania Inferior, Germania Superior, and Britannia. Because of their heavy weight and high intrinsic value relative to minor copper denominations, sestertii of this era remained in commercial circulation for decades. Many specimens of RIC 588 survive in moderately to heavily worn condition, frequently found in deposits alongside Flavian and Trajanic bronze, demonstrating that they continued to exchange hand-to-hand well into the second century AD. In some frontier military sites, worn Neronian sestertii bear countermarks applied during the civil wars of AD 68 to 69 or under the early Flavians, reflecting administrative re-validation of circulating currency in periods of fiscal disruption.

References

1. Coins of the Roman Empire in the British Museum, Volume I: Augustus to Vitellius. pp. 261-264
2. The Western Coinages of Nero (Numismatic Notes and Monographs, No. 161). pp. 132-145
3. Online Coins of the Roman Empire: RIC I (second edition) Nero 588. ric.1(2).ner.588
4. The Roman Imperial Coinage, Volume I: From 31 BC to AD 69 (revised edition). p. 184, no. 588