Philip I Silver Antoninianus, RIC IV Philip I 24C

Monetary Context and the Roman Millennium

During the mid-third century AD, the Roman imperial monetary system depended heavily upon the antoninianus, or radiate double denarius, as its primary silver transactional currency. Introduced under Caracalla in 215 AD and restored as the principal circulating silver denomination under Gordian III, the denomination by 248 AD had undergone progressive debasement. Under Philip the Arab, who reigned from 244 to 249 AD, the coin contained roughly forty to forty-five percent silver, alloyed predominantly with copper and trace metals. In 248 AD, Philip commemorated Rome's bimillenary midpoint: the completion of one thousand years since Romulus traditionally founded the city in 753 BC. To commemorate this monumental occasion, the administration mounted the Ludi Saeculares, or Secular Games, featuring elaborate religious rituals, imperial vows, and arena spectacles. The massive expenditure required to fund the games, public distributions, and military donatives necessitated an extensive emissions program from the Rome mint. RIC IV Philip I 24C represents a core ideological element of this commemorative output. Rather than depicting the arena beasts that characterize other reverse designs of the series, this coin focuses on the formal institutional record of the anniversary through a dedicated monument.

Production Standards and the Rome Mint

All standard numismatic authorities assign RIC IV Philip I 24C to the central mint at Rome. During this period, the Rome mint was organized into several numbered workshops, or officinae, which divided production tasks and tracked coin outputs. While several contemporaneous Saeculares issues bear explicit Greek or Roman numerals in their exergues indicating workshop assignments, the cippus type typically omits workshop numbers, circulating as a general central emission. Metallurgical analyses of mid-third-century antoniniani reveal that silver blanks were cast, heated, and struck rapidly with steel dies. The alloy for Philip's billon coinage hovered between 35 and 45 percent silver purity, yielding an intrinsic precious-metal value substantially below the coin's mandated tariff of two denarii. Weight standards for Philip's radiate antoniniani generally targeted approximately 3.9 to 4.2 grams, though individual specimens demonstrate considerable flan variance ranging from under 3.0 grams to well over 4.8 grams. Die alignment is predominantly regular, adhering mostly to a standard twelve-o'clock or six-o'clock orientation typical of official Roman workshop practice.

Obverse Iconography and Imperial Portraiture

The obverse of RIC IV Philip I 24C displays a right-facing bust of Philip the Arab. In accordance with the established conventions for the double denarius, the emperor wears a radiate solar crown, a visual device that distinguished the denomination from the laureate denarius. The specific bust variety designated by subtype 24C features Philip draped and cuirassed, combining classical civic drapery with imperial scale or plate armor. The portraiture is rendered in the characteristic realistic style of the mid-third-century soldier-emperors: a heavy, squared jaw, closely cropped hair and beard indicated through short linear die incisions, and deeply furrowed brow lines suggesting gravitas, martial alertness, and executive resolve. Die engravers captured the emperor's mature physiognomy while maintaining the formal dignified ethos of imperial portraiture required for state religious celebrations.

Reverse Iconography: The Commemorative Cippus

The reverse of the type features a central low monumental column, commonly termed a cippus or pedestal, inscribed with the epigraphic text COS III. In Roman civic and religious architecture, cippi served as markers for sacred boundaries (pomerium), boundary milestones, or pedestals for votive inscriptions and state sacrifices. In the context of the 248 AD Saeculares celebrations, the cippus functions as an enduring stone monument to the solemn vows (vota) undertaken during the games for the preservation of the empire into its second millennium. The inscription directly references Philip's third consulship, which commenced on January 1, 248 AD. Flanking the monument is an open field framed by the circular legend. Unlike adjacent Saeculares issues that showcased lions, stags, antelopes, or the She-wolf suckling Romulus and Remus, the cippus conveyed a sober message of constitutional legality, temporal renewal, and divine favor granted to the imperial collegium.

Epigraphy and Legend Structure

The epigraphy of RIC IV Philip I 24C is executed in compact Roman capitals. The obverse legend reads IMP PHILIPPVS AVG, an abbreviated Latin title expanding to Imperator Philippus Augustus. This formula highlights the emperor's supreme military command (Imperator) alongside the sacred supreme dignity (Augustus), omitting familial names and earlier titles in favor of a concise, bold imperial designation. The reverse legend reads SAECVLARES AVGG, expanding to Saeculares Augustorum. The term translates as 'Secular [Celebrations] of the Emperors', with the doubled terminal 'G' indicating the joint rule of the Augusti: Philip I and his young son and co-ruler, Philip II. On the shaft of the low column itself, the short inscription COS III denotes Consul Tertium, marking the emperor's third tenure as consul and firmly grounding the religious event within the civil magistracies of 248 AD.

Typology and Chronological Classification

In the classification framework established by Mattingly, Sydenham, and Sutherland in The Roman Imperial Coinage (Volume IV, Part III), entry 24 encompasses the cippus reverse type issued under Philip I. The catalog separates the entry into distinct sub-varieties based on the emperor's obverse attire: 24A covers the radiate, cuirassed bust; 24B covers the radiate, draped bust; and 24C designates the combined radiate, draped, and cuirassed bust facing right. The issue is chronologically fixed to 248 AD by the combination of Philip's third consulship (COS III) and the explicit reference to the Secular Games. It belongs to the second main commemorative emission of that year, coordinated with parallel issues bearing the portraits of Empress Otacilia Severa and Philip II, as well as a series of bronze sestertii and middle bronzes bearing identical reverse imagery.

Circulation, Hoard Evidence, and Survival

The millennial coinage of 248 AD was struck in massive quantities and disseminated widely across the western and eastern provinces through military payments, commercial networks, and civic distributions. Because the silver content of the antoninianus continued to decline rapidly during the subsequent reigns of Decius, Trebonianus Gallus, and Valerian, antoniniani of Philip the Arab were subject to Gresham's law and heavy hoarding. As newer, lower-grade billon coins entered circulation in the 250s and 260s AD, populations retained the comparatively better silver issues of the 240s AD. Consequently, RIC IV Philip I 24C appears with high frequency in major third-century hoards discovered across Roman Britain, Gaul, the Rhine frontier, and the Danubian provinces. The vast majority of surviving specimens display light to moderate circulation wear, illustrating that while these coins carried specific religious and ideological messaging for the millennial festivities, they served as everyday currency long after the celebration concluded.

References

1. Coin Hoards and Hoarding in the Roman Empire. pp. 95-120
2. The London Mint of Constantius and Constantine. Introductory survey of third-century billon standards
3. Online Coins of the Roman Empire: RIC IV Philip I 24C. ric.4.ph_i.24C
4. The Roman Imperial Coinage, Vol. IV, Part III: Gordian III to Uranius Antoninus. pp. 71-72, no. 24