Philip I Silver Antoninianus

Monetary Context and Weight Standards

By the accession of Philip I in AD 244, the Roman silver monetary system had undergone fundamental structural shifts. The denarius, which had formed the bedrock of Roman imperial currency since the Republic, was reduced to a negligible fraction of mint output, effectively replaced by the radiate antoninianus as the standard silver denomination for commerce, tax collection, and military pay. Theoretical weight standards for the antoninianus during Philip's reign typically hovered around 3.8 to 4.2 grams, though surviving specimens demonstrate wide operational variance, commonly falling between 3.2 and 4.6 grams. The metallic composition was markedly debased, with silver fineness hovering between forty and forty-five percent, the remainder being alloyed copper and trace elements. This debasement reflected mounting fiscal pressures, including the enormous indemnity of five hundred thousand gold denarii or sesterces paid to Shapur I of the Sasanian Empire to conclude peace in AD 244, as well as ongoing military expenditure along the Danube and substantial infrastructure projects in Philip's ancestral homeland, Philippopolis in Syria.

Mints and Workshop Organization

The overwhelming bulk of Philip's silver antoniniani was produced at the imperial mint in Rome. Under Philip's administration, the Rome mint formalized an internal division into six distinct workshops (officinae). During the celebrated Secular Games emission of AD 248, these workshops placed systematic officina marks in the reverse fields or exergues, utilizing Greek numerals (A, B, Gamma, Delta, E, and Z) or Latin numerals (I through VI) to track production across the six branches. This innovation provided scholars with an exceptionally clear view of administrative accountability in the mid-third-century imperial mint. In addition to Rome, an important branch mint operated in the east, traditionally identified as Antioch in Syria. The eastern mint is distinguished by a distinctive regional portraiture style, characterized by bolder facial modeling, different bust truncations, and subtle variations in reverse iconography and legend orthography.

Obverse Iconography and Radiate Crown

The obverse of the antoninianus invariably portrays the emperor wearing the radiate crown, the numismatic mark of value signifying a double unit that distinguished the denomination from the laureate denarius. Philip is presented with realistic, veristic facial features characteristic of mid-third-century soldier-emperors: a close-cropped military haircut, a short-trimmed beard, and heavy facial contours reflecting mature authority. His bust is typically draped and cuirassed, viewed from either the front or the back (three-quarters rear view), often showing the pteruges and shoulder straps of Roman armor. Across the five-year reign, subtle evolutionary changes in portrait style can be observed at Rome, progressing from portraits that closely recalled the youthful features of his predecessor Gordian III toward more individualized, stern depictions. Parallel obverse designs were simultaneously issued for his family: Empress Otacilia Severa was depicted diademed with her bust resting on a crescent (the feminine equivalent of the radiate crown), while Philip II appeared as bare-headed or radiate Caesar and later as radiate Augustus.

Reverse Types and the Secular Games

The reverse repertoire of Philip's antoniniani encompasses both routine imperial propaganda and singular commemorative themes. Traditional types invoked standard virtues and imperial blessings: Annona Augusti (grain supply), Felicitas Temporum (happy times), Fides Militum (loyalty of the army), Pax Aeterna (eternal peace), and Victoria Augusti (imperial victory). Far more distinctive are the coinages struck in AD 248 to celebrate the one-thousandth anniversary of the founding of Rome (the Ludi Saeculares). These special reverses feature the legend SAECVLARES AVGG around an extraordinary assortment of ceremonial types and arena animals presented at the games. Distinct workshops produced reverses depicting a lion (officina I or A), a she-wolf suckling the twins Romulus and Remus (officina II or B), a stag (officina III or Gamma), an antelope or gazelle (officina IV or Delta), a deer (officina V or E), and a capricorn (officina VI or Z). Other related anniversary reverses depict a pillar or cippus inscribed with the commemorative text, an elephant driven by its mahout, and the temple of Roma or Venus and Rome (Templum Urbis), proclaiming the dawn of a new age (SAECVLVM NOVVM).

Inscriptions and Epigraphic Formulas

Obverse legends on Philip's Rome-mint antoniniani are standardized and follow a clear chronological evolution. The earliest issues of AD 244 utilize the brief titular formula IMP M IVL PHILIPPVS AVG (Imperator Marcus Iulius Philippus Augustus). By late AD 244 or early 245, this was expanded to IMP PHILIPPVS AVG, which became the standard obverse formula for the remainder of the reign at Rome. Eastern mint emissions often retained variants such as IMP C M IVL PHILIPPVS P F AVG (Pius Felix Augustus). Reverse legends emphasize the emperor's constitutional offices and civic program, recording his iterative consulships (COS I, COS II, COS III) and tribunician power (P M TR P, progressing through P M TR P VI). Votive and dynastic legends, including CONCORDIA AVGG and AEQVITAS AVGG, explicitly feature the double 'G' abbreviation, signifying the joint rule of the two Augusti after Philip II was elevated to co-emperor in AD 247.

Typology and Chronological Classification

The chronological framework for Philip's antoniniani was systematically established in Harold Mattingly and Edward Sydenham's Roman Imperial Coinage (RIC IV Part III). The coinage is divided into distinct chronological phases keyed to tribunician renewals and political events. The first phase (AD 244-245) covers the consolidation of power after the Persian settlement, featuring initial obverse forms and reverses promoting peace (Pax Fundata cum Persis on rare aurei, and Pax Aeterna on antoniniani). The second phase (AD 245-247) reflects Philip's northern campaigns against the Carpi and Germanic tribes along the Danube, during which he took the victory titles Germanicus Maximus and Carpicus Maximus, reflected on his reverse legends as Victoria Carpica. The third phase (AD 247-248) marks the elevation of his son Philip II to Augustus and the massive monetary preparation for the millennial celebrations, culminating in the dated Saeculares series of AD 248. The final phase (AD 248-249) saw urgent military emissions reflecting the usurpations of Pacatianus and Jotapianus, and ultimately the defense against Decius, before Philip's defeat and death at the Battle of Verona in autumn AD 249.

Hoard Evidence and Monetary Circulation

Extensive hoard evidence across the Roman Empire confirms that Philip's antoniniani circulated widely in massive numbers throughout both western and eastern provinces. Major hoards discovered in Britain, France, Germany, the Balkans, and the Levant, such as the Dorchester and Gibraltar hoards, regularly contain dense concentrations of Philip's radiate coins alongside those of Gordian III and Trajan Decius. Because Philip's antoniniani were struck at a relatively stable fineness compared to the catastrophic silver debasements under Valerian and Gallienus a decade later, they remained in active circulation for several decades, subject to Gresham's law. In hoards buried during the late 260s and early 270s AD, Philip's coins frequently show substantial wear, having circulated alongside severely debased billon radiates containing less than five percent silver. Their ubiquitous presence in archaeological contexts attests to the scale of Philip's output and the complete integration of the antoninianus into everyday military and civilian trade.

References

1. Coin Hoards and Hoarding in the Roman Empire. pp. 82-104
2. The Monumental Coinage of Philip I: The Saecular Games and Rome's Millennium. pp. 15-45
3. Coinage in the Roman Economy, 300 B.C. to A.D. 700. pp. 125-135
4. Roman Coins from the Earliest Times to the Fall of the Western Empire. pp. 130-142
5. The Roman Imperial Coinage, Volume IV, Part III: Gordian III to Uranius Antoninus. pp. 55-105