Caelius Hilarianus

Caelius Hilarianus was a Roman senator (vir clarissimus) active during the second half of the fourth century CE. He is known from an altar dedicated to Magna Mater and Attis Menotyrannus discovered among the inscriptions traditionally associated with the Vatican Phrygianum. The inscription, dated 13 May 377, records an extensive series of priestly functions and constitutes one of the clearest attestations of senatorial participation in Mithraic worship during Late Antiquity (TNMM 620; Griffith 1993; Walsh 2016).

In the inscription, Caelius Hilarianus describes himself as duodecemvir urbis Romae, pater sacrorum and hieroceryx of Mithras, priest of Liber, and priest of Hecate (TNMM 620). His accumulation of priestly offices reflects a broader phenomenon among members of the late Roman aristocracy, several of whom simultaneously held positions in Mithraic, Dionysiac, Hecatean, Isiac, and Metroac cults. Comparable combinations of religious titles are attested for contemporaries such as Ulpius Egnatius Faventinus, Iunius Postumianus, and Alfenius Ceionius Iulianus Kamenius (Griffith 1993; Walsh 2016).

The Mithraic titles borne by Caelius Hilarianus are particularly noteworthy. While the title pater clearly identifies him as a senior member of a Mithraic community, the designation hieroceryx (“sacred herald”) appears repeatedly in fourth-century aristocratic inscriptions and seems to have formed part of the ceremonial vocabulary adopted by these elite circles. Modern scholarship has debated the extent to which such aristocratic devotees represented a continuation of earlier Mithraic communities or a transformed expression of late pagan religiosity. Whatever the interpretation, the inscription demonstrates that Mithraic priesthoods remained prestigious among sections of the Roman senatorial elite as late as 377 CE (Griffith 1993; Clauss 1992; Walsh 2016).