Marcus Simplicius Simplex

Marcus Simplicius Simplex was a Roman auxiliary prefect active in the early third century AD and one of the known dedicants of the Mithraeum at Carrawburgh (Brocolitia) on Hadrian’s Wall. He is known exclusively from an altar dedicated to Deo Invicto Mithrae, discovered in front of the sanctuary’s apse together with the altars of Lucius Antonius Proculus and Aulus Cluentius Habitus (TNMM 180; Richmond & Gillam 1951; CIMRM 847-848; Chalupa 2023).

Unlike the other two prefects, Simplicius identified himself only as praefectus, omitting the name of his military unit. Because his altar stood alongside those of the prefects of the Cohors I Batavorum Antoniniana, most scholars conclude that he likewise commanded that cohort and dedicated his monument slightly later, when specifying the unit had become unnecessary within the established sanctuary (Walsh 2016). On onomastic grounds, Eric Birley further suggested that Simplicius may have originated in Germania Inferior, although this remains speculative (Birley 1934; McCarty & Egri 2020).

His altar is one of the most remarkable monuments from Roman Britain. Its front shows Mithras identified with Sol, wearing a radiate crown and holding the solar whip. The rays of the crown were pierced through the stone so that the light of a lamp placed behind the altar illuminated the image, creating a striking visual effect during ritual ceremonies. Comparable examples are rare in Britain, making the monument an important witness to the sophisticated use of light in Mithraic worship.

Although the altar itself cannot be dated precisely, its archaeological context places it within the flourishing phase of the Carrawburgh Mithraeum during the early third century AD. Together with the dedications of Proculus and Cluentius Habitus, it illustrates the close association between the command of the Cohors I Batavorum and the patronage of the sanctuary, suggesting that successive prefects played an important role in its maintenance and religious life.