NGRef: SO0562
OSMap: LR147
Type: Fort

Plan of Castell Collen fort
(adapted from Collingwood fig.6)
Road: SSW (13) to Caerav (Powys)
NE (4) to Dolav Gaer (Powys)
Margary #621: S (17) to Castell Madoc
Postulated Road: SSW (7.5) to Penmincae

The Roman Fort at Castell Collen


"A 'Flag Section' of the Second Augustan Legion made [this fort]."

(J.R.S. XLVII (1957) p.227 no.5)

SO056628 c.510 x 360 ft
(c.155 x 110 m)
c.4¼ acres
(c.1.7 ha)

The original fort was rectangular in outline, measuring about 510 feet from north-north-east to south-south-west, by about 360 feet transversely (c.155 x 110 m), within the ramparts, giving an occupation area of about 4¼ acres (c.1.7 ha). At some later date the northern defences were contracted by about 140 feet, giving an almost square outline and reducing the internal area to about 3 acres (c.1.24 ha).

"At Castell Collen (Fig.6) the length of the fort (originally, it would seem a Flavian fort of ordinary type) was reduced by 40 [sic.; should be 140] feet. A cross-wall was built cutting off most of the retentura, and forming the back wall of a square castellum measuring 410 feet externally each way (i.e. probably 360 to 370 feet square internally, or 3 acres. Wheeler Prehist. and Rom. Wales, 230.)" (Collingwood, p.38)

The first excavations at Castell Collen were conducted in 1911 but the most productive were under Alcock during 1954-6. There were two main periods of occupation, the original timber-built fort on this site was of typical Flavian type and dated c.75AD. The earliest samian recovered was a piece of form 15/17 (c.55-80) and two shards of form 18 (c.60-80). Any earlier fort in the area must have been sited elsewhere, "possibly in the Crossgates - Penybont area" (Webster RAC). The lack of occupation evidence dating to the Hadrianic period may indicate that the fort was abandoned by the Roman military and the site later re-occupied. Antonine samian ware shows occupation in the late-second century, and during the Severan period the retentura of the fort was reduced in length by about 140 feet by the building of a cross-wall, thus converting the fort into a square plan with an internal width of c.365 feet and an area of about 3 acres, at the same time, the defences were replaced in stone. The only dateable material found after this is some third century pottery, which may indicate that the garrison was withdrawn sometime before the fourth (JRS 1953 p.86; Webster p.115).

The Epigraphic Evidence from Castell Collen

Stone Found in 1911 Near Entrance to Principia

...P P COS... ...IMA...

"[...] Pater Patriae, Consul [...]"

(RIB 414; sandstone tablet fragment; part restored)

There are four inscriptions on stone recorded in the R.I.B. for the Castell Collen fort. There are three 'centurial' stones, an ansate building-stone found within the fort in 1911 is missing the right side and reads merely > ... "The century of [... built this]." (RIB 417), the other two stones were found re-used in the local area and are shown below. The remaining stone is part of an inscription recording the dedication of the principia or regimental headquarters building in the centre of the fort (RIB 414, vide supra).

Stone Found in 1926 in Field-wall Close to Fort


"The century of Marcus has made forty-six paces [of rampart]."

(RIB 415; sandstone ansate building-stone)

Stone Found in 1878 in Llanbadarn Fawr Church


"[Made by] the century of Flavius Flavinus."

(RIB 416; sandstone ansate building-stone)

Other Roman Sites in the Area

There is another fort three miles to the north-west at Dolau Gaer (SO0166) with marching camps beyond at Trefal (SO0268), St Harmon (SN9871) and Esgairperfedd (SN9269). There is also another fort lying seven miles to the south-south-east at Colwyn Castle (SO1053). In addition, to the south of the fort on Llandrindod Common there are at least eighteen military practice works (SO0559/SO0560).

See: The Archaeology of Roman Britain by R.G. Collingwood (Methuen, London, 1930);
Air Reconnaissance of Southern Britain by J.K. St. Joseph in J.R.S. xliii (1953) pp.81-97;
The Roman Inscriptions of Britain by R.G. Collingwood and R.P. Wright (Oxford 1965);
Rome Against Caratacus by Graham Webster (Batsford, London, 1993);
All Latin-English translations, including any inherent mistakes, are my own.
Page Citation: Kevan White (2018) "Roman Britain: CASTELL COLLEN"