Philip the Arab Copper-Alloy Sestertius

Monetary Context and Economic Environment

During the reign of Philip the Arab (244 to 249 AD), the monetary system established by Augustus was experiencing accelerating transformation and fiscal stress. The double denarius, or antoninianus, had become the primary vehicle for state expenditure, military payouts, and tax collection. As the silver content of the radiate antoninianus declined, the nominal tariffing between base silver and token copper-alloy coinage grew increasingly precarious. The sestertius, traditionally valued at one-fourth of a denarius or one-eighth of an antoninianus, saw its real purchasing power eroded by inflationary pressures. Despite this challenging backdrop, Philip continued the heavy minting of sestertii. Rather than functioning primarily as an active daily market denomination in frontier camps, the large flans of the sestertius provided a vital platform for civic ideology and public propaganda in Rome and urban Italy. The issue of large bronze pieces reassured both the Senate and the populace that administrative stability and traditional institutions endured despite ongoing frontier crises.

Mints, Metallurgy, and Production Techniques

The vast majority of Philip's imperial sestertii were manufactured at the mint of Rome. While some regional or provincial bronzes were struck in Greek imperial cities or colonial centers such as Viminacium and Antioch, standard imperial issues carrying the senatorial formula S C were concentrated in the capital. Metallurgically, early imperial sestertii were struck in orichalcum, a distinct copper-zinc alloy valued for its bright, golden appearance. By the middle of the third century AD, virgin zinc ores (calamine) were scarce in imperial minting, leading to heavy recycling of older scrap metal. Chemical analyses reveal that Philip's sestertii were struck on a quaternary alloy composed of copper mixed with diminished percentages of zinc, alongside variable additions of tin and lead. Weight standards also continued a downward trajectory: while second-century AD sestertii typically weighed 25 to 28 grams, Philip's specimens commonly ranged between 16 and 22 grams. Flans were cast in molds and struck hot between iron dies, often displaying bevelled edges, irregular contours, and minor striking fissures.

Obverse Iconography and Styles

The obverse of Philip's sestertius uniformly presents the right-facing imperial portrait. Unlike the radiate crown reserved for the double denomination (the antoninianus in silver or the dupondius in base metal), the sestertius displays Philip wearing a classical laurel wreath. The imperial bust is typically depicted with drapery, cuirass, or a combination of both. Stylistically, die engravers at Rome portrayed Philip with a compact head, tightly cropped hair, a close-trimmed military beard, and pronounced facial furrows. This veristic portraiture echoed the rugged soldier-emperor aesthetic introduced during the Severan period while projecting maturity, vigilance, and gravitas. Variations exist in die execution, ranging from deeply modeled, expressive portraits early in the reign to flatter, more stylized renderings toward 248 and 249 AD.

Reverse Iconography and Themes

The broad surface of the sestertius allowed elaborate thematic programs across Philip's five-year reign. Traditional allegorical personifications predominated: Annona highlighted grain distribution and civic abundance, Pax celebrated negotiated treaties on the eastern frontiers, Fides Militum and Virtus courted the loyalty and strength of the legions, while Aequitas, Felicitas, and Salus emphasized equity, prosperity, and divine health. The most celebrated reverse program occurred in 248 AD to mark the thousandth anniversary of Rome's foundation (the Saeculum Novum). Philip commemorated the Ludi Saeculares with a famous menagerie series depicting exotic animals exhibited in the Colosseum, including lions, stags, antelopes, elks, and elephants. Complementary types featured a commemorative cippus column inscribed with festival notices or figures of Rome seated, accompanied by the standard legend SAECVLARES AVGG. All standard reverse types included the senatorial affirmation S C in the field or exergue, upholding long-standing constitutional convention.

Inscriptions and Epigraphic Formulas

Epigraphy on Philip's sestertii was concise, formal, and strictly standardized. The dominant obverse inscription was IMP M IVL PHILIPPVS AVG (Imperator Marcus Julius Philippus Augustus). In occasional early or special issues, extended variants such as IMP CAES M IVL PHILIPPVS AVG appear. Reverse inscriptions proclaimed core administrative virtues or event milestones, including ANNONA AVGG (Abundance of the Augusti), PAX AETERNA (Eternal Peace), FIDES EXERCITVS (Loyalty of the Army), or VICTORIA AVGG (Victory of the Augusti). Coins celebrating the millennium displayed SAECVLARES AVGG (Centennial Games of the Augusti) or SAECVLVM NOVVM (The New Era), occasionally featuring MILIARIVM SAECVLVM on celebratory columns. The letters S C, signifying Senatus Consulto ('by decree of the Senate'), occupied either the lower exergue or were split across the left and right fields of the reverse die.

Typological Development and Chronology

Philip's sestertii can be organized chronologically through tribunician iterations and major historical milestones recorded by the Rome mint. The earliest series in 244 AD emphasized legitimation and political accord following the death of Gordian III, celebrating concord, peace, and initial military titles (TR P COS). From 245 to 247 AD, reverses reflected the emperor's northern campaigns along the Danube and the elevation of his son, Philip II, to co-emperor, marked by pluralized titles ending in AVGG. The apex of typological output arrived in 248 AD with the Saecular Games, designated by Philip's second and third consulships and the coordinated issuance of the animal and cippus series across multiple mint workshops (officinae). The final phase in late 248 and 249 AD reflected mounting military peril and usurpations, turning back to themes of military fidelity and fortifying imperial prestige shortly before Philip's defeat and death at the Battle of Verona.

Hoarding, Circulation, and Post-Striking Life

Archaeological finds reveal that Philip's sestertii circulated primarily within Italy and the western provinces, including Gaul, Britain, and along the Rhine and upper Danube frontiers. In these areas, legacy copper-alloy coin pools were still necessary for low-value local transactions. However, hoarding patterns demonstrate that base-metal coins were increasingly abandoned in favor of silver antoniniani as inflation worsened. Sestertii struck under Philip are frequently found in worn, battered condition within mixed site deposits from the 250s and 260s AD, indicating prolonged circulation alongside worn Trajanic, Antonine, and Severan bronzes without substantial replacement. By the reign of Gallienus and the subsequent monetary collapse of the late 260s AD, sestertius production effectively ceased across the empire, marking Philip's issues as one of the final flourishing chapters of the imperial sestertius.

References

1. Coin Hoards and Hoarding in the Roman Empire. ch. 4
2. The Metallurgy of Roman Coinage: From the Reform of Nero to the Reform of Trajan Decius. pp. 512-530
3. Orichalcum and Related Ancient Alloys (Numismatic Notes and Monographs No. 151). pp. 95-115
4. Roman Coins from the Earliest Times to the Fall of the Western Empire. pp. 130-145
5. The Roman Imperial Coinage, Vol. IV, Part III: Gordian III to Uranius Antoninus. pp. 68-105