Caerhun (Canovium) Roman Fort

Flavian Auxiliary Fort (AD 69–96) and Vicus

Canovium or Canovivm was a fort in the Roman province of Britannia. Its site is located at Caerhun in the Conwy valley, in the county borough of Conwy, in North Wales.

About the year 1650 the antiquarian Samuel Lee unearthed a hypocaust and tiles stamped LEG XX V, and Gale in 1719 reported others, recently unearthed, bearing the legend LEG X, which may have been broken. In 1801 Samuel Lysons uncovered a bath-house, 128 feet (39m) long, outside the north-east defences of the fort, along with tile-stamps marked LEG XX VV.

This fort is contemporary with the forts at Cicucium (Brecon Gaer/Y-Gaer) and Segontium (Caernarfon), being built around 75AD. This is a square fort, each side measuring 410 feet within the ramparts, giving an occupation area of 3¾ acres. Defenses consisted of a 20 foot wide clay bank, fronted by two ditches. The gateways and internal buildings were of timber construction.

The size of the fort and the arrangement of its interior buildings suggest that Caerhun housed a Cohors Peditata Quingenaria, a regiment of foot-soldiers nominally five-hundred strong. The names of none of the garrison units stationed at Canovium are known.

Plan of the fort at Canovium Adapted from Webster’s The Roman Imperial Army (fig.45)

Additions in stone were made in the first quarter of the second century, and early rather than late in that period. The outer margin of the clay rampart was cut off to a width of 2 feet, and a stone wall 6 feet thick at its base built between the rampart and ditch. The inner ditch was filled up soon afterwards in order to strengthen the foundation of this wall. … The gateways also were rebuilt in stone. The east gate (porta praetoria) was a double opening with guard-rooms, singular in having its two arches of different widths (15 feet and 5 feet respectively). The new south gate was a double opening with no guard-rooms; but one of the arches seems to have been blocked up during construction for use as a guard-room. At the same time the internal buildings were all reconstructed in stone.” (Collingwood, p.37)

Excavation has revealed two timber periods in the early history of this fort, rebuilding being carried out sometime during Flavian times. The sacellum in the centre of the camp was the first building to be replaced in stone during the reign of Trajan, followed by the rampart-wall in Hadrian’s reign. Hadrianic and Antonine samian ware shows continued occupation through these times, but the well in the principia was filled around 196/7AD, which may indicate either destruction or desertion at this time. Occupation at the fort was soon resumed, however, as attested by the building of a new cook-house behind the rampart around 235, and continued occupation throughout the third and fourth centuries is proven by pottery and coins dateable to both these periods. The last coin recovered from the site is one of Gratian (367-383).

After the fort was destroyed in c.200AD, the civilian settlement or vicus outside the defences was only sporadically occupied until the 4th century when it was finally abandoned. There were Roman copper mines at Pen-y-Gogarth (Great Orme’s Head), eight miles north of the settlement near Llandudno at the mouth of the River Conwy.

Classical References to Canovium

The Antonine Itinerary was a list of routes and posting-stations used by the Roman army of the late-second century, the British section of this document has fifteen such itineraries, and the Caerhun fort is included in Iter XI – Item a Segontio Devam ‘Itinerary Eleven – The route from Segontium to Deva‘. The route is listed as 74 (Roman) miles long, starting from Segontivm (Caernarfon, Gwynedd) the next station Conovio is 24 miles away, which can only be Caerhun. From here Iter XI proceeds another 18 miles to Varis (St. Asaph, Clwyd?) then on to its eastern terminus at Deva (Chester, Cheshire), a further 32 miles. The seventh-century Ravenna Cosmology (R&C#83) lists Caerhun as Canubio, where it appears between the entries for Segontivm and Mediolanvm (Whitchurch, Shropshire).

The only texts reported in the Roman Inscriptions of Britain are not very helpful; a building stone inscribed …OA… (RIB 437) which is undecipherable, and also a lead letter D (RIB 438), which had originally been inset into a stone inscription, now lost.

Milestones From The Canovium Area

Four Roman milestones have been found in the countryside around Caerhun, all can be reasonably dated; the most important one was found on Rhiwiau Farm, 7 miles west of Caerhun and mentions the name of the Canovium Fort (vide RIB 2265 supra), another (RIB 2266 vide infra) was found on the opposite side of the road on the same farm, and one more along the same Roman road but only 4 miles from Caerhun (RIB 2267 infra) and another was recently discovered nearby at Bwlch-y-Ddeufaen, 3½ miles west of the fort (JRS xlvi 1956, p.148, no.11; vide infra).

Togo-Translation: “To the unconquered Augustus, the divine Constantinus Pius, son of the Augustus.”
RIB: JRS 1956.11; 307-37AD

The find-spot of the last Roman milestone mentioned is nearby a visible section of the old Roman road from Caerhun to Caernarfon (NGRef: SH 725 714), and this entire stretch of the road north of the Afon Tafalog abounds with ancient hut-circles, cairns, burial chambers and standing stones.

References for Canovivm

  • The Roman Imperial Army by Graham Webster (Constable, London, 1979);
  • Air Reconnaissance in Britain, 1973-76 by J.K. St. Joseph in J.R.S. lxvii (1977) p.151;
  • The Roman Inscriptions of Britain by R.G. Collingwood and R.P. Wright (Oxford 1965);
  • The Archaeology of Roman Britain by R.G. Collingwood (Methuen, London, 1930);
  • The Military Aspects of Roman Wales by Prof. F. Haverfield (London 1910; pp.28-31);

Map References for Canovivm

NGRef: SH7770 OSMap: LR115, OL17

OS National Grid Reference: 776704
Dimensions: c.410 x 410 ft (c.125 x 125 m)
Area: c.3¾ acres (c.1.5 ha)

Roman Roads near Canovivm

S (10) to Brynygefeiliav (Gwynedd) WSW (15) to Caemetta Iter XI: ENE (19) to St Asaph WSW (20) to Segontivm

Sites near Caerhun (Canovium) Roman Fort