Severus Alexander Sestertius, RIC IV Severus Alexander 635b

Monetary and Historical Context

The issue of the sestertius RIC IV Severus Alexander 635b falls into the final phase of Severus Alexander's reign, dating between 231 and 235 AD. During this period, the Roman state faced acute military pressures, beginning with Ardashir I's incursions into Roman Mesopotamia and Syria, which required the emperor's personal mobilization of the eastern legions. This military transition led to a notable shift in Roman imperial monetary iconography. For the majority of his reign following his accession in 222 AD, Alexander's coinage had favored motifs emphasizing civic harmony, piety, senatorial cooperation, and judicial moderation under the guidance of his mother, Julia Mamaea. By 231 AD, the arrival of sustained warfare prompted the revival of martial deities on official issues, most prominently Mars Ultor, the avenger of Roman honor. The sestertius served as the principal large copper-alloy denomination of the Roman monetary system, holding a tariff of one-fourth of a silver denarius or one-eighth of an antoninianus. Large-denomination brass and bronze issues played a vital role in everyday commercial payments, administrative outlays, and provincial market integration throughout the central and western Mediterranean.

Mint Organization and Production Techniques

All regular imperial sestertii of this series were manufactured at the central mint of Rome. The Rome mint was organized into distinct officinae (workshops), which shared the burden of striking gold, silver, and aes coinage. Production involved the casting of thick, circular flans composed of orichalcum (a copper-zinc alloy) or related bronze alloys. These heated or cold flans were positioned manually between an anvil die and a hand-held punch die before being struck by hammer blows. Because the mint did not employ mechanical collars, the resulting flans vary in thickness and edge uniformity, displaying typical radial striations and minor edge splits. Die alignment at Rome during the Severan period was generally regular, commonly favoring an upright or nearly upright die axis (approximately 12 o'clock or 6 o'clock). While the nominal target weight for third-century sestertii remained centered around 20 to 22 grams with diameters typically ranging from 28 to 32 millimeters, individual blanks demonstrate the normal variance of bulk ancient minting practice, in which alloy batches were regulated by weight per pound rather than by precision adjustment of individual blanks.

Obverse Typology and Imperial Iconography

The obverse of RIC IV Severus Alexander 635b presents a mature portrait of Severus Alexander facing right. He is depicted wearing a laurel wreath, tied at the back of the head with ribbons falling toward the nape of the neck. The bust configuration specific to subtype 635b features drapery visible across the left shoulder, leaving the remainder of the bust line cleanly defined. This treatment stands in clear typological contrast to subtype 635a, which presents an undraped head or bust, and subtype 635c, which displays complete drapery across both shoulders or paludamentum. The portrait style reflects the official court manner of the early 230s AD: the youthful features of Alexander's earlier coinage have been replaced by a square jaw, shorter clipped hair, and a light military beard rendered through fine die chisel marks. This iconographic evolution aligned his public image with the traditional expectations of an imperator actively commanding field operations against external adversaries.

Reverse Iconography of Mars Ultor

The reverse design of this type features the war god Mars advancing to the right. Mars is depicted in full military attire, wearing a crested helmet and a light chlamys floating behind his torso or draped across his arm. In his right hand, he holds a vertical or slightly inclined spear point-forward, while his left hand supports an oval or circular military shield held against his side or shoulder. Flanking the lower fields of the composition is the senatorial formula 'S C' (Senatus Consulto). The image of Mars Ultor was deeply rooted in imperial traditions established by Augustus following the construction of the Temple of Mars Ultor in the Forum of Augustus. Under Severus Alexander, the revival of Mars Ultor served a specific ideological purpose: it justified the logistical sacrifices of the Persian campaigns and later the mobilization along the German frontier by framing Roman offensive operations as righteous acts of retribution against foreign aggression.

Epigraphy and Legend Structure

The inscriptions on RIC IV Severus Alexander 635b are composed in clear, capital Latin lettering engraved along the inner circumference of the beaded border. The obverse reads IMP ALEXANDER PIVS AVG (Imperator Alexander Pius Augustus). This legend was introduced in 231 AD to mark Alexander's adoption of the title 'Pius' alongside the formal assumption of the supreme military title 'Imperator' as a permanent praenomen. The omission of the full filiation and older pontifical formulas seen in his early coinage created a more concise, militarized formula. The reverse legend reads MARS VLTOR (Mars the Avenger), identifying the deity depicted in the central field. The letters 'S' and 'C' appear across the left and right fields, representing 'Senatus Consulto' ('by decree of the Senate'). While base-metal coinage remained administratively under the imperial palace and its mint officials, the retention of 'S C' preserved the traditional constitutional fiction that Rome's brass and copper denominations derived authority from the Senate.

Typological Distinction and Chronology

The Mars Ultor sestertius series forms a coherent group within the late bronze coinage of Severus Alexander, catalogued collectively under RIC IV 635. Harold Mattingly and Edward Sydenham segregated the type into distinct lettered varieties based entirely on the treatment of the imperial bust. Subtype 635a possesses a simple laureate head without drapery; subtype 635b represents the laureate bust with slight drapery over the left shoulder; and subtype 635c features a laureate, draped, and cuirassed bust. Related issues were simultaneously struck in other denominations, including silver denarii and base-metal dupondii and asses, demonstrating a synchronized programmatic release across the Rome mint. The chronological window for RIC 635b is securely placed between 231 AD, when the PIVS AVG legend was adopted during preparations for the Persian war, and March 235 AD, when Alexander and his mother were assassinated at Mogontiacum (Mainz) during their northern campaign against the Alamanni.

Circulation, Hoarding, and Deposition

Sestertii of the Mars Ultor type enjoyed an extensive circulation footprint across the Roman Empire, particularly within the western provinces of Roman Britain, Gaul, the Germanies, and along the Rhine-Danube limes where troop concentrations required constant supplies of small-change and fiduciary coinage. Archaeological site finds and large bronze coin hoards from Britain and the European mainland regularly contain specimens of RIC 635b, often showing varying degrees of wear from decades in daily transactions. During the mid-third century AD, the progressive debasement of the silver antoninianus eroded the relative purchasing power of base-metal coins. Sestertii of the Severan era continued to circulate alongside diminished local radiates until the monetary reforms of Aurelian in 274 AD and Diocletian in 294 AD made the traditional sestertius obsolete, leading to the burial of mixed-reign aes hoards or the melting of bronze flans for secondary metalwork.

References

1. Coins of the Roman Empire in the British Museum, Volume VI: Severus Alexander to Balbinus and Pupienus. pp. 195-197
2. Ancient History from Coins. pp. 24-27
3. Online Coins of the Roman Empire: RIC IV Severus Alexander 635b. RIC IV Severus Alexander 635b
4. The Roman Imperial Coinage, Volume IV, Part II: Macrinus to Pupienus. pp. 119-120, no. 635b