Whatever its origins, the Roman cult seems to have been successful mainly in
Italy, in the northwestern provinces, especially Germania Superior, and in all the
Danubian provinces. Elsewhere, in north Africa including Egypt, Spain, western Gaul,
Britain, and throughout the east Mediterranean, it is uncommon and extraneous –
associated predominantly with military sites and harbor towns. In Germany, the
focus of early excavation upon the limessuggested that there, too, it was primarily
a military phenomenon. But recent discoveries on non-military sites (e.g. Biesheim
on the Rhine near Colmar; Wiesloch near Heidelberg; Mündelsheim and Güglingen
near Heilbronn; Sechtem near Bonn; Gellep near Krefeld) now suggest that unpre-
tentious mithraea, sometimes made of wood or even turf, which would have been
irrecoverable by older archaeological procedures, were to be found in many minor
settlements, often on the outskirts of town, well away from the recognized sites of
civic cult, and sometimes surrounded by a fence (as at Forum Claudii Vallensium/
Martigny near Lake Geneva).
Such structures could only have accommodated small numbers. But there are
several larger temples – the cellaof the largest known mithraeum, recently discovered
in the grounds of what was probably the summer villa at modern Els Munts (on the
Costa Dorada, north of Tarragona) of the governor of Hispania Tarraconensis, and
presumably used by the slaves and freedmen of his household (familia), measures
30 by 8.7 meters, giving a usable area, excluding the kitchens, of 260 square meters.
In light of this discovery, if confirmed, it is worth speculating on the likely size of
the mithraeumthat is known to have existed inside the imperial domuson the Palatine
ad 209–11 (ILS4270); the mithraeumbeneath the Baths of Caracalla measures 23
by 9.70 meters, that is, 223 square meters, without the side rooms. Such mithraea
had correspondingly large congregations: an important inscription found at Virunum
in Noricum, originally intended to record the names of the 34 men who contributed
to repairing one of the mithraeathere inad 183, was afterwards used to record
the names of new members, 64 of them over the following 18 years, varying in
number from eight in the years 184 and 192 to one in the years 186, 190, 194,
196, and 201 (AE1994, 1334). Some of these later members seem to have decided
inad 201 to go off and found a new mithraeum, presumably (caution: suspiciously
few deaths are recorded for this period) because the old one was too crowded
(AE1994, 1335).
The social composition of this mithraeumis also instructive, because it seems to
confirm what we can infer from the evidence at Ostia: apart from a small number
of locally fairly eminent members, the great majority are freedmen from the main
local families, or rather their descendants. There is one peregrinus, one slave, and
no women. At Pons Aeni, a mithraeumat the important crossing of the Salzburg–
Augsburg road over the Inn, one of the local potters, Ma[rt]inus or Ma[tern]inus,
dedicated a sigillatavessel that he had carefully decorated with an image of Mithras
in barbotine technique, expensive because time-consuming (Gordon 2004: 270,
fig. 8). The impression of a relatively self-conscious, relatively prosperous, group is
supported by the inference from caches of sacrificial bones buried within or near
several mithraea. At Quintana/Künzing on the Danube in Raetia, for example, the
great majority of bones were those of suckling pigs and chickens, quite different from
396 Richard Gordon