Constantius II Silver Siliqua

Monetary Context and Denominational System

The silver siliqua emerged during the monetary reorganizations initiated by Diocletian and reformed by Constantine I to restore a functional silver denomination alongside gold and base-metal coinages. Under Diocletian, the argenteus had been struck at 96 to the Roman pound, but by the 320s AD Constantine introduced the denomination modern numismatists term the siliqua, derived from the keration or carob seed weight unit. Initially tariffed at 1/96 of a Roman pound (roughly 3.41 grams), the silver piece served as a bridge between the gold solidus and fractional bronze coinage. During the reign of Constantius II, systemic economic pressure, ongoing frontier campaigns, and internal conflict led to decisive weight reductions. In the late 340s and early 350s AD, the imperial treasury lowered the normal weight of the standard circulating siliqua to 1/144 of a Roman pound, yielding a theoretical weight of approximately 2.27 grams, with real-world flan weights commonly falling between 1.80 and 2.15 grams. Numismatists distinguish between the earlier heavy siliqua and this later light siliqua, which became the baseline silver denomination for the later fourth century. Despite fluctuations in flan weight, the purity of the metal remained remarkably consistent, with metallurgical analyses confirming fineness levels generally above 92 percent fine silver. The light siliqua acted as a vital medium for military donatives, bureaucratic stipends, and administrative tax payments across both the eastern and western halves of the Empire.

Mint Organization and Regional Production

Production of siliquae under Constantius II was geographically widespread, reflecting the peripatetic movement of the imperial court and strategic military funding needs. In the western provinces, mints such as Treveri (Trier), Lugdunum (Lyon), and Arelate (renamed Constantina under Constantius II) produced significant quantities, though output was frequently disrupted during the usurpation of Magnentius between 350 and 353 AD. In Italy and the Illyrian frontier, Rome, Aquileia, Siscia, and Sirmium served as critical production centers, with Sirmium striking substantial silver during imperial residences in the 350s AD. In the eastern provinces, where Constantius II exercised long-term control before reuniting the empire, Constantinople, Nicomedia, Cyzicus, and Antiochia operated large silver workshops. Mintmarks in the exergue followed rigorous bureaucratic protocols, combining an abbreviated mint name with workshop officina numerals or letters, such as SMN for Sacra Moneta Nicomedia, SIRM for Sirmium, or LVG for Lugdunum. These exergual signatures were frequently accompanied by supplemental symbols such as palm branches, stars, or wreaths that denoted specific emission sequences. The quality of engraving varied by region, with eastern mints like Constantinople and Antioch known for fine, standardized lettering and delicate diadems, while western mints exhibited distinctive local stylistic nuances in bust proportions and lettering.

Obverse Typology and Imperial Iconography

The obverse iconography of Constantius II siliquae presents a clear progression corresponding to his rising political status. Earliest emissions struck during the lifetime of Constantine I portray Constantius II as Caesar, typically showing a youthful, bare-headed or laureate bust facing right, draped and cuirassed. Following his elevation to Augustus in 337 AD, the portraiture transitioned to signify supreme imperial authority. The predominant mature portrait depicts the emperor facing right, diademed, draped, and cuirassed. The imperial diadem appears in several distinct artistic variants: early Augustan issues frequently employ a laurel wreath tied with fillets or a rosette diadem composed of square or circular gems set into the band, whereas later issues almost universally adopt the pearl diadem, consisting of two parallel strings of pearls flanking a central jewel. The imperial countenance is rendered in the stylized, idealized Late Roman manner, characterized by large almond-shaped eyes, an upright nose, and a placid expression intended to convey divinely sanctioned majesty and eternal vigilance rather than realistic portraiture. Minor variations include left-facing busts or specialized ceremonial attire, although right-facing diademed busts form the overwhelming majority across all operational mints.

Reverse Iconography and Imperial Themes

Reverse imagery on the siliquae of Constantius II is dominated by institutional themes of imperial continuity, military triumph, and civic piety. The most common reverse type across the entire empire features the imperial vota inscribed within a circular laurel wreath, usually reading VOTIS XXV MVLTIS XXX, VOTIS XXX MVLTIS XXXX, or VOTIS XXXX. This formula, celebrating imperial vows undertaken and anticipated for future decades, served as an effective propagandistic tool ensuring public loyalty and projecting dynastic longevity. Outside the votive series, personifications and military allegories appear on notable issues. The seated personification of Rome or Constantinopolis holding a globe, scepter, or cornucopia, often with one foot resting on an imperial prow, symbolizes the dual capital system of the fourth century. Other reverse compositions include Victoria walking or standing, holding a wreath and palm branch, or Victoria advancing left holding a trophy, paired with legends celebrating imperial victory over external enemies and rebellious usurpers. A rarer ceremonial type depicts Constantius II standing in military dress, holding a labarum inscribed with the Christogram and accompanied by standard military insignia, underscoring the Christianization of official imperial symbolism.

Inscriptions and Epigraphic Formulas

Obverse inscriptions on Constantius II siliquae adhere to precise titulary formulas that distinguished his constitutional rank. As Caesar between 324 and 337 AD, the legends typically read FL IVL CONSTANTIVS NOB C or FL IVL CONSTANTIVS NOB CAES, abbreviating Flavius Iulius Constantius Nobilissimus Caesar. Following his accession as Augustus in 337 AD, the titulary shifted to D N CONSTANTIVS P F AVG, representing Dominus Noster Constantius Pius Felix Augustus. This standard legend was utilized at virtually every imperial mint for the remainder of his reign, occasionally appearing in expanded forms such as CONSTANTIVS AVGVSTVS on specialized ceremonial series. On the reverse, the predominant legend pattern consists of votive inscriptions enclosed inside the laurel wreath, such as VOTIS XXX MVLTIS XXXX, signifying vows fulfilled for thirty years of rule and prospective vows for forty years. Unenclosed narrative reverse legends include FELICITAS REIPVBLICE, VICTORIA AVGVSTORVM, VIRTVS EXERCITVS, and GLORIA ROMANORVM, celebrating civic prosperity, imperial victory, military valor, and the glory of Rome. In the exergue, detailed abbreviations designate the mint and workshop, for example CONSP for Constantinople, SIRM for Sirmium, or SCON for Arelate, providing vital epigraphic criteria for regional attribution.

Typological Evolution and Chronological Framework

The chronological development of Constantius II's siliqua coinage can be divided into four primary phases. The first phase spans 324 to 337 AD, during his tenure as Caesar, characterized by heavy siliquae of approximately 3.4 grams carrying youthful portraits and shared dynastic types issued under Constantine I. The second phase, from 337 to 350 AD, encompasses the tripartite rule of Constantius II alongside his brothers Constantine II and Constans. During this period, eastern mints controlled by Constantius II struck substantial silver series with early vota like VOTIS XX MVLTIS XXX alongside seated personification types. The third phase, from 350 to 353 AD, coincides with the civil war against the usurper Magnentius and the temporary elevation of Vetranio in Illyricum. During this conflict, control of western mints shifted, prompting heavy propaganda issues, while Siscia and Sirmium struck critical emergency silver for the imperial field army. The fourth phase, from the defeat of Magnentius in 353 AD until Constantius II's death in 361 AD, witnessed the full consolidation of his sole rule. This phase was defined by the empire-wide standardization of the light siliqua, struck at approximately 2.0 to 2.2 grams and predominantly bearing the VOTIS XXX MVLTIS XXXX reverse wreath type, creating the massive silver stock that circulated across the Mediterranean world.

Circulation Patterns, Hoards, and Clipping

Siliquae of Constantius II achieved an exceptionally wide geographic distribution and remained in active circulation for several decades after his death in 361 AD. Large quantities moved beyond official administrative centers to pay military garrisons stationed along the Rhine, Danube, and Persian frontiers. Major coin hoards discovered throughout Britain, northern Gaul, Germany, and the Balkans contain substantial proportions of Constantius II light siliquae, frequently found alongside issues of Julian, Valentinian I, and Valens. In Roman Britain, these coins played an extraordinary monetary role: during the late fourth and early fifth centuries AD, siliquae of Constantius II were systematically subjected to clipping, a practice in which the outer silver margins were sheared off to harvest precious metal while preserving the central portrait and imperial legend for continued token circulation. Hoards such as the Hoxne Hoard, the East Harptree Hoard, and numerous continental deposits illustrate that Constantius II's votive siliquae represented the backbone of commercial silver liquidity in the western provinces until the breakdown of Roman civic administration in the fifth century AD.

References

1. The Roman Imperial Coinage, Volume VII: Constantine and Licinius (A.D. 313-337). Introduction, pp. 1-35
2. The Late Roman Gold and Silver Coins from the Hoxne Treasure. pp. 39-55
3. The Family of Constantine I, A.D. 337-364 (RIC VIII). Introduction, pp. 45-88
4. The Roman Silver Coinage of the Fourth Century A.D.: The Siliqua and the Miliarense. pp. 281-300
5. The Roman Imperial Coinage, Volume VII: Constantine and Licinius (A.D. 313-337). pp. 1-778
6. The Roman Imperial Coinage, Volume VIII: The Family of Constantine I (A.D. 337-364). pp. 1-578