CIMRM 511 - Inscription by the priest of the Mithraeum at the Domus Augustana. Vatican Museum, Rome.

511. Tabula marmorea. CIL VI 2271; MMM II No. 35. D(is) M(anibus) / L. Septimius Aug(ustorum trium) lib/(ertus) pater et sacerdos invicti / Mithrae domus augustanae / fecit sibi et Cosiae Primitivae / coniugi benemerenti libertis liberta/busque posterisq(ue) eorum. Tres Augusti intelligendi sunt Severus et Antoninus Augusti et Geta Caesar. From this inscription it appears that Mithras had also found acceptance with the Imperial Court.

I.e. To the spirits of the dead, L. Septimius, freedman of the three emperors, father and priest of unconquered Mithras at the imperial palace, made this for himself and for Cosia Primitiva, his well-deserving spouse and their free boy and girl children.

(By the "three emperors" should be understood as Severus, and his sons Antoninus (Caracalla), and Geta.)

According to Adrian van Heck¹ this item is now in the Vatican museum.