Several inscriptions at Ostia mention a certain Caius Celius Ermero, always referred to as the antistes of that place. One, engraved on a small marble altar, was found in the mithreum of the Pareti dipinte, in a large patrician house. Another with an identical dedication is engraved on a small marble altar still in situ in the mithreum of the Palazzo Imperiale (CIMRM 259). Finally, this man is also the dedicatee of two statues of Cautes and Cautopates also found in the mithreum of the Palazzo Imperiale.
As R. Marchesini has shown, the bases supporting the statues of Cautes and Cautopates are in fact altars that were replaced and transformed into bases on which the statues of the dadophores were placed (which already appear in relief on the main face of each altar/base). At the same time, the previous inscriptions (with the exception of the consular date of 162) were removed and the dedications of Ermeros were engraved. In all probability, the four altars were originally located in the mithraum of the Pareti dipinte. A damnatio memoriae having struck the unknown dedicatee of the two altars with dadophoric reliefs, Ermeros appropriated these monuments as local antiquities (Huius loci).
It was for this reason that he had the two small altars CIMRM259 and 269 (= no. 93b) placed in this same mithreum. When the so-called Palazzo Imperiale was built, the same Ermeros probably had three of the four monuments moved to the new place of worship. It is perhaps then that the altars were transformed into pedestals, surmounted by statues that curiously reproduce the reliefs.
—(2021) Les Cultes de Mithra dans l'Empire Romain
Other brothers from Ostia
The marble inscription mentions Caelius Ermeros as antistes of this place.
C. Caelius E[r]/meros / antis/tes h[ui]/us loc[i] / fecit / s(ua) p(ecunia).
Caius Caelius Ermeros, antistes of this place, made, at his expense.
The sculptures of Cautes and Cautopates from the Mitreo del Palazzo Imperiale may have been reused from an older mithraeum in Ostia.
C(aius) Caelius / Ermeros / ant/istes huius lo/ci fecit sua / pec(unia).
Posit(a)e XV k(alendas) / febr(u)arias / Q(uinto) Iunio Rus/tico / L(ucio) Plaut[io] / Aquilin[o] / co[(n)s(ulibus)].
Caius Caelius Ermero, antistes of this place, made, at his own expense.
Erected on the fifteenth day before the calendas of February, Quintus Iunius Rusticus and Lucius Plautius Aquilinus being consuls.