Gaius Iulius Castinus

Gaius Iulius Castinus was a Roman senator, military commander and governor of Pannonia Inferior, attested as a worshipper of Mithras at Aquincum in the early 3rd century CE.

Before his governorship in Pannonia, Castinus commanded the Legio I Minervia, probably between 205 and 208. He subsequently served as legatus Augusti pro praetore of Pannonia Inferior from 209 to 212/213. Since Pannonia Inferior had only one legion, the governor also commanded the Legio II Adiutrix stationed at Aquincum (Latteur 2010).

At Aquincum, Castinus dedicated an altar to Deus Invictus Mithras (TNMM 502; CIMRM 1774; CIL III 3480):

Deo Invicto / Mithrae C(aius) / Iul(ius) Cast/inus leg(atus) Aug(usti) / pr(o) pr(aetore).

Castinus was therefore one of the highest-ranking individuals known to have worshipped Mithras in Pannonia Inferior. Latteur stresses his exceptional position within the military hierarchy, while Clauss (1992) describes him as one of the most important generals of the Severan period.

The altar cannot, however, be securely associated with any of the five archaeologically identified mithraea of Aquincum. Clauss (1992) includes Castinus among the Mithraic evidence from Aquincum that cannot be assigned to a particular sanctuary and specifically questions the attribution of his altar to the so-called Mithraeum V on the basis of findspot alone.

Castinus’ high rank does not necessarily mean that he held a leading position within a Mithraic community. As Szabó (2026) notes, Castinus and other prominent senators have sometimes been interpreted as leading figures in the Danubian cult of Mithras. He follows Gordon (2009), however, in cautioning that senatorial worshippers in provincial contexts may simply have followed local religious tendencies. An alternative interpretation is that such high-ranking individuals acted as patrons of Mithraic communities rather than as their religious leaders. The surviving evidence does not allow Castinus’ precise role within the cult to be established.

The Roman army is undoubtedly the socio-professional milieu most affected by the cult of Mithras in the province of Pannonia. With a few exceptions, the Mithras cultores were military of the Adiutrix Legion II, stationed in Aquincum. It can be seen that these Mithras-worshipping soldiers are found at all levels of the military hierarchy. The most important of these worshippers is certainly the legate of the legion, Gaius Tulius Castinus: Deo inuicto/ Mithrae C(aius)/ lul(ius) Cast/inus leg(atus) Aug (usti)/ pr(o) pr(aetore). ’To the unconquered god Mithra, Gaius Iulius Castinus, legate of Augustus the procurator [made this offering].’ The legate of a legion, a member of the senatorial order, led the entire legion: he was therefore a person of primary importance. Tulius Castinus was also the governor of the province: in provinces with only one legion, the governor also led the legion located in the territory under his authority. Gaius Iulius Castinus was in office in Inferior Pannonia from 209 to 212, which makes it possible to date the inscription fairly precisely. The career of this legate is also fairly well known. Before becoming legate of Inferior Pannonia, he was also legate of the legion I Minervia (205-208). He seems to have enjoyed the favour of the emperor Caracalla afterwards. This inscription indicates that he was in Lower Pannonia at the beginning of the reign of Elagabal, which makes it possible to date the inscription to the beginning of the 3rd century.

—Olivier Latteur. La Diffusion du culte de Mithra dans les province danubiennes