SEGONTIUM
Caernarvonshire, N Wales.
An
auxiliary fort of 2.2 ha in the command of Legio
XX V.V., garrisoned by a cohors milliaria equitata and
in the 3d c. by the quingenary Cohors I Sunicorum.
Founded ca. A.D. 78 at the time of Agricola's Welsh
campaign (Tac.
Agric. 18); occupied (with intermissions) until ca. 390, after the garrison was withdrawn
by Maximus (the Macsen Wledig of the Mabinogi)
thereafter appearing as the Seguntienses (
Not. Dig. occ.
7.49) in the command of the Comes Illyrici.
The cardinal position of Segontium as the NW outpost
of the Welsh military region, as well as the importance
of the copper mines of Anglesey and Caernarvonshire, explain its long occupation. The fort, terminus of an
Antonine Itinerary route, occupies the top of a rounded hill above the tidal mouth of the Seiont (and the famous
Edwardian castle adjacent to it); it was excavated mainly
in 1920-23. The much reduced circuit of the walls and
three of the four double gateways are visible; inside, part
of the latera praetorii (headquarters with underground
strongroom in the sacellum and added tabularium, with
hypocaust; commandant's house; workshops) and six
centurial barracks and a forage store in the retentura,
all arranged per scamnum. Outside, a Mithraeum (built
over) was excavated, and near the cliff above the river
are the remains of a large walled compound. The museum at the site is a branch of the National Museum of Wales (Cardiff).
BIBLIOGRAPHY
R.E.M. Wheeler,
Segontium and the
Roman Occupation of Wales (1923-24)
MPI; O. Cuntz,
ed.,
Itineraria Romana (1929-) 73-74; G. C. Boon, “A
Temple of Mithras . . . ,”
Archaeologia Cambrensis
(1960)
MPI; id.,
Segontium Roman Fort (1963)
MPI; id. in V. E. Nash-Williams,
The Roman Frontier in Wales,
ed. M. G. Jarrett (1969)
MPI; id.,
Amgueddfa: Bulletin
of the National Museum of Wales 18 (1974).
G. C. BOON
