Nero Copper and Orichalcum As

Monetary Context and the Neronian Currency Reform

For the first decade of Nero's reign, the imperial mint at Rome struck no regular aes coinage, relying instead on circulating Julio-Claudian copper and brass along with abundant countermarked or provincial issues. When bronze production resumed around AD 62 to 64, it formed part of a comprehensive monetary reorganization. Nero adjusted the weights of the gold aureus and silver denarius, reducing their intrinsic metal content, and simultaneously overhauled the token base metal system. Under the established Augustan arrangement, the sestertius and dupondius were composed of orichalcum (a zinc-copper alloy valued at approximately double the rate of copper), while the as and quadrans were manufactured from pure red copper. Nero's mint administrators broke radically with this convention by attempting an all-orichalcum denomination series. The as was struck not only in traditional copper at approximately 10 to 11 grams, but also in orichalcum at a theoretical reduced weight of roughly 8.5 grams. This experiment introduced substantial complexity into everyday market transactions, as the public was required to evaluate value through metal color, weight, and portrait conventions rather than alloy composition alone.

Mints and Metallurgical Production

The production of Nero's asses was divided between two principal Western imperial facilities: Rome and Lugdunum. Rome initiated the series, carrying out the primary orichalcum experiment with high artistic refinement. Die cutting at Rome achieved an exceptionally high sculptural relief, rendering dramatic muscularity and detailed coiffures. Lugdunum resumed large-scale aes minting around AD 64 to 65 to supply the Western provinces and Rhine legions. The products of Lugdunum are typically distinguished by a small globe placed at the tip of the emperor's neck truncation, though stylistic traits such as a flatter relief and distinct lettering forms also separate them from Roman dies. Metallurgically, the orichalcum asses required careful zinc cementation processes, but fluctuations in zinc content caused variations in tone from bright yellow to brassy brown. Pure copper asses were produced in parallel, especially at Lugdunum, where the local populace and military markets favored the established heavy copper standard. By AD 66 to 67, the mint of Rome curtailed the production of orichalcum asses, conceding to standard copper flans for the denomination.

Obverse Portraiture and Attributes

The obverse of Nero's asses features dynamic and realistic portrait heads that broke away from the classicizing, idealized Julio-Claudian style of Augustus, Tiberius, and Claudius. Nero is depicted as an adult ruler with a fleshy jaw, pronounced double chin, and a distinctive hairstyle consisting of tiered waves dressed in curls across the brow (coma in gradus formata), reflecting contemporary court fashion. The bust is presented either facing right or left. Head treatments vary: the emperor is shown bareheaded or wearing a laurel wreath. Unlike the dupondius, which used the radiate crown to mark its double value when struck in the same metal as the as, the as never displays a radiate crown. On Lugdunum issues, a small globe or occasionally an aegis appears at the base of the neck. On some early orichalcum asses, experimental mark of value marks or distinct drapery treatments were tested before the standardized bare or laureate busts became predominant across the denomination.

Reverse Iconography and Propaganda

The reverse types of Nero's asses delivered pointed civic, religious, and military propaganda. One of the most famous types depicts the Temple of Janus with its twin doors firmly shut, commemorating the universal peace achieved across the empire following the conclusion of the Parthian campaigns by Gnaeus Domitius Corbulo. Another common motif is Victory advancing or floating, holding a shield inscribed S P Q R, an allusion to military triumphs and the stability of the regime. The Ara Pacis Augustae (Altar of Peace) is represented with elaborate decorative reliefs, linking Nero directly to the golden age and religious monuments of Augustus. Nero's personal artistic pretensions are manifested on the Apollo Citharoedus type, where the god is depicted in long flowing robes playing a lyre, closely mirroring the emperor's public performances. A further type shows the Genius of the Emperor (Genio Augusti), standing beside an altar while holding a patera and cornucopia, reinforcing traditional sacrificial piety and imperial benevolence.

Inscriptions, Titulature, and Denominational Marks

Obverse inscriptions on the as record Nero's expanding imperial titulature, typically rendering variations of NERO CAESAR AVG GERM IMP or IMP NERO CAESAR AVG P MAX TR P P P. The placement of the title IMP either as a praenomen or cognomen provides critical chronological criteria for separating earlier issues from later strikings. On the reverse, thematic inscriptions interpret the iconography: the Temple of Janus type features the explicit declaration PACE P R TERRA MARIQ PARTA IANVM CLVSIT ('The peace of the Roman people having been established on land and sea, he closed the Temple of Janus'). The lyre-player type is often accompanied by PONTIF MAX TR P IMP P P or simply the standard senatorial authorization S C (Senatus Consulto). The letters S C appear prominently across nearly all reverse types in the fields, maintaining the constitutional convention that base metal coinage was authorized through the Senate. A limited group of early orichalcum asses also bore explicit marks of value, such as a numeral or letter T, in an attempt to make denomination recognition immediate.

Typological Evolution and Chronological Sequence

The chronological progression of Nero's asses is divided into three distinct phases between AD 62 and AD 68. Phase one, from approximately AD 62 to 64, encompassed the pre-reform trials and the initial launch of the reform at Rome, during which orichalcum was introduced for all base metal denominations. In this opening phase, dies were executed with meticulous detail, experimenting with denomination marks and innovative reverse types such as Apollo Citharoedus and the Genius. Phase two, beginning around AD 65, coincided with the opening of aes production at Lugdunum and the expansion of mass-produced copper asses alongside diminishing orichalcum strikings. The closed Temple of Janus and Victory with shield types became dominant during this period, celebrating the peaceful settlement with Parthia and the coronation of Tiridates I in Rome. Phase three, from AD 66 until Nero's suicide in June AD 68, saw the total abandonment of the orichalcum as in favor of heavy copper flans, while the obverse titulature stabilized with IMP NERO CAESAR AVG P P or similar formulas until production collapsed amidst the rebellions of Vindex and Galba.

Circulation, Hoards, and Afterlife

Nero's asses circulated extensively throughout the Roman Empire, although their patterns of recovery reveal stark geographical and metallurgical divisions. Orichalcum asses, concentrated in Italy and specific urban markets, were subject to rapid wear and selective withdrawal due to their intrinsic zinc value and potential confusion with dupondii. Conversely, the heavy copper asses struck at Lugdunum formed the backbone of military and day-to-day trade across Gaul, Britain, and the German frontier zones. Excavation assemblages from military camps such as Vindonissa and frontier settlements in Roman Britain frequently yield worn Neronian copper asses, demonstrating their longevity in circulation well into the reigns of Vespasian, Domitian, and Trajan. During the civil wars of AD 68 to 69, Neronian asses were occasionally countermarked by rival factions to revalidate or claim loyalty. When the Flavian dynasty consolidated power, the dual-metal experiment for fractional aes was formally discarded, returning the as permanently to the pure copper standard established under Augustus.

References

1. The Western Coinages of Nero (Numismatic Notes and Monographs 161). pp. 1-120
2. Coins of the Roman Empire in the British Museum, Volume I: Augustus to Vitellius. pp. clxi-clxxviii, 214-275
3. The Roman Imperial Coinage, Volume I: From 31 BC to AD 69 (Revised Edition). pp. 133-185