Gaius Sacidius Barbarus

Gaius Sacidius Barbarus was a centurion of the Legio XV Apollinaris and the dedicator of one of the earliest securely datable Latin inscriptions to Mithras. His marble altar, found at Carnuntum and probably associated with Mithraeum I (TNMM 43), was dedicated Invicto Mitrhe in fulfilment of a vow (TNMM 503; CIL III 4418; CIMRM 1718). Since the legion left Carnuntum for the East by 114 CE, the dedication provides firm evidence for the presence of Mithras at Carnuntum before that date (Chalupa 2016; Kremer 2024).

Barbarus has consequently played an important role in discussions of the early spread of Mithraic worship through the Roman army. Since Cumont (1899), it was often proposed that he had either been recruited during the eastern campaigns of the Legio XV Apollinaris or encountered the cult there before returning with the legion to Carnuntum in 71 CE. On this reconstruction, and assuming a normal military career, his altar has sometimes been dated considerably earlier than 114, even to the Flavian period (Daniels 1975; Bricault et al. 2021).

This eastern-transmission hypothesis is no longer considered secure. Gordon (2009) questioned both the early dating and the assumption that Barbarus had been recruited in the East, while Kremer (2024) stresses that neither his name nor his rank supports such an origin and that the evidence for an early transmission of Mithraic worship from the eastern provinces remains problematic. Clauss (1992), indeed, regarded Barbarus as Italian. His geographical origin and the circumstances in which he became a devotee of Mithras therefore remain unknown.

Whatever his origin, Barbarus provides exceptionally early evidence for Mithraic worship within the military environment of the Danube. His altar demonstrates that a centurion of the Legio XV Apollinaris was making a formal vow to the invincible Mithras at Carnuntum no later than the early second century, making the dedication an important landmark in the documented development of Roman Mithraism (Chalupa 2016; Kremer 2024).

The centurion Caius Sacidius Barbarus, bearer of a rare gentilice attested in particular in the region of Mount Hermon, in Syria, has carved out a place of choice in the historiography of Mithraic studies for being potentially the author of the oldest Latin dedication to the god.

The legion XV Apollinaris, to which he belonged at the time of his dedication, was stationed at Carnuntum on three occasions: from 9 to 62; then from 71 to 86, after having followed Corbulo in Armenia and participated in the war in Judea, a period during which Sacidius may have been involved; finally from 105 to 113, after having fought in Dacia, and before leaving Pannonia for good.

The rasura that covers the last three lines of the text has removed either the name of Nero or, more probably, that of Domitianus if one accepts the Syrian origin of the dedicator and his probable entry into the legion in the 60s. If this reasoning is correct, the inscription should be dated to the beginning of Domitianus’s reign, between 81 and 86, and would be contemporary with Stace’s [Thebaid, which also mentions Mithras in a Roman context for the first known time.]

—Bricault; Roy (2021) Les Cultes de Mithra dans l’Empire romain.