Caligula Sestertius, RIC I (second edition) Gaius/Caligula 33

Monetary and Political Context

When Gaius Caesar Germanicus, commonly known as Caligula, ascended the imperial throne in March of AD 37, the Roman monetary system was still governed by the structural arrangements established under Augustus. The sestertius served as the principal large-format base-metal denomination, valued at four asses, two dupondii, or one quarter of a silver denarius. Beyond its routine economic utility in retail transactions, military accounting, and state distributions, the sestertius functioned as the premier physical canvas for imperial political communication due to its broad flan. During the protracted final decade of Tiberius, central bronze output at Rome had grown conservative and irregular, frequently dominated by consecration issues, repetitive civic virtues, or passive senatorial dedications. Gaius immediately revolutionized this medium upon his accession by utilizing the sestertius to broadcast an aggressive dynastic realignment. Having survived the catastrophic downfall of his mother Agrippina the Elder and his elder brothers Nero Caesar and Drusus Caesar during the reign of Tiberius, Gaius placed the surviving core of his family at the center of Roman public life. By pairing his own portrait with full-length depictions of his three sisters, this coin type declared the complete restoration, security, and dynastic abundance of the Julian-Claudian line under the surviving children of Germanicus.

Production Standards and Minting

The sestertii catalogued under RIC I (second edition) Gaius/Caligula 33 were struck exclusively by the central imperial mint at Rome. They were fabricated from orichalcum, a copper-zinc alloy prized for its golden, bright appearance, which sharply distinguished it from the darker, pure copper used for asses and quadrantes. In accordance with the early Julio-Claudian metrological standard, sestertii of this type were struck to a theoretical target weight approximating one Roman ounce (uncia), or roughly 27 to 28 grams, though surviving individual specimens naturally exhibit a wider operational distribution ranging from approximately 25 to 30 grams. Flan diameters typically measure between 34 and 37 millimeters. Die engraving for this inaugural issue attained high technical and artistic quality, characterized by crisp, elegant letterforms and deeply modeled figural relief. Die axes are predominantly oriented at either twelve o'clock or six o'clock, reflecting the regularized mechanical practices of the Roman officinae. Production occurred on a substantial scale during the first issue period, indicating an intensive initial effort to flood Roman and provincial financial networks with the new regime's ideological messaging.

Obverse Iconography

The obverse of RIC 33 features the laureate head of Gaius oriented to the left. This portraiture represents a distinct stylistic break from the austere, aged realism of late Tiberian coinage, presenting Gaius with youthful features, a straight aquiline nose, prominent forehead, and finely waved locks of hair brought down the nape of the neck and brushed across the temple. The choice of a left-facing bust is characteristic of Gaius's initial bronze coinage at Rome, a departure from the right-facing profile that had been standard on Tiberius's portrait bronzes. The laurel wreath encircling his head rests securely on his hair, with its two ties falling gracefully behind the neck. Surrounding the portrait runs the unbroken obverse legend, positioned carefully within a neat outer border of dots. The engraving captures a deliberate balance between realistic dynastic physiognomy, echoing the revered profile of his father Germanicus, and imperial majesty appropriate for the sole ruler of the Roman world.

Reverse Iconography and Attributes

The reverse iconography of RIC 33 represents one of the most innovative and daring designs in Julio-Claudian numismatics. It depicts the emperor's three living sisters standing side by side in frontal view, each head turned slightly and distinguished by divine and allegorical attributes. On the left stands Agrippina the Younger, depicted in the guise of Securitas; she holds a cornucopiae in her right hand, while her left arm rests upon a column, symbolizing enduring civic stability and unshakeable dynastic peace. In the center stands Drusilla, portrayed as Concordia; she grasps a patera in her right hand and cradles a cornucopiae with her left, embodying concord, marital harmony, and unity within the imperial house and the wider state. On the right stands Julia Livilla, represented as Fortuna; she holds a rudder in her right hand and an upright cornucopiae in her left, personifying favorable imperial fortune and the guidance of the state. Each sister is dressed in long, flowing stola and palla, with draped folds rendered with classical delicacy. This triple assimilation of living imperial women to cardinal Roman virtues transformed Caligula's immediate family into visible guarantors of the Roman commonwealth.

Inscriptions and Epigraphy

The inscriptions on RIC 33 are explicit, concise, and politically programmatic. The obverse legend reads C CAESAR AVG GERMANICVS PON M TR POT, representing Gaius Caesar Augustus Germanicus, Pontifex Maximus, Tribunicia Potestate. This formula records Gaius's legal praenomen and cognomina alongside his acceptance of the supreme pontificate (PON M) and his initial investiture with tribunician power (TR POT), lacking any numerical iteration. The reverse field is inscribed AGRIPPINA DRVSILLA IVLIA, with the personal names of the three sisters placed adjacent to or above their respective figures, leaving no ambiguity regarding their individual identities. Below the figures in the exergue, or split within the lower field, appears the authoritative formula S C (Senatus Consulto), signifying that the bronze coinage was issued under the formal sanction of the Senate. The epigraphy is characterized by well-proportioned, classical capitals with pronounced serifs, showcasing the highest standard of Julio-Claudian die cutting.

Typology and Chronological Evolution

Numismatists securely place the issuance of RIC 33 between the late spring of AD 37 and the early summer of AD 38. The obverse inscription provides an absolute terminus post quem of March AD 37, when Gaius assumed the titles Augustus and Tribunicia Potestate, followed shortly by the office of Pontifex Maximus. Because the obverse legend records TR POT without an iteration number, the dies for this type were produced prior to the renewal of his tribunician power as TR POT II in early AD 38. Subsequent strikings of the Three Sisters sestertius incorporate updated obverse legends reflecting this second tribunician power, catalogued as RIC 42. Production of the Three Sisters composition came to an irrevocable halt following the sudden illness and death of Drusilla on June 10, AD 38. Following her subsequent deification under the name Diva Drusilla, she was commemorated through distinct consecration issues, making the continued minting of the triad of living sisters obsolete. Typologically, RIC 33 represents the primary, inaugural variant of this short-lived series.

Circulation, Countermarking, and Survival

Sestertii of RIC 33 were dispersed widely across the central Mediterranean, Italy, and the western provinces, where military legions and administrative centers required vast quantities of high-value base-metal currency. Archaeological and hoarded evidence reveals that specimens circulated heavily throughout Gaul, the Rhine frontier, and Hispania. In frontier contexts, some surviving examples bear post-Caligulan countermarks, applied during the reigns of Claudius or Nero to revalidate base-metal coins in circulating cash pools. Following Gaius's assassination in January of AD 41, the Roman Senate instituted an informal damnatio memoriae, ordering his statues destroyed and attempting to recall his bronze coinage from public use. Although Dio Cassius notes that the Senate sought to melt down his bronze, practical monetary necessity prevented the total demonetization of this currency; large numbers of Caligulan sestertii remained in long-term circulation until well into the Flavian period. Nevertheless, many pieces exhibit intentional defacement, vigorous wear, or edge chiseling. Surviving high-grade specimens of RIC 33 remain among the most celebrated treasures of early imperial Roman numismatics.

References

1. Coins of the Roman Empire in the British Museum, Volume I: Augustus to Vitellius. pp. 152-153, nos. 36-37
2. Roman Provincial Coinage, Volume I: From the Death of Caesar to the Death of Vitellius. pp. 310-312
3. Online Coins of the Roman Empire: RIC I (second edition) Gaius/Caligula 33. RIC I (2nd ed.) Gaius 33
4. The Roman Imperial Coinage, Volume I: From 31 BC to AD 69 (Revised Edition). pp. 104-110, no. 33