Caerleon Roman Fortress (Isca Silurum)

Situated on the south-western edge of the modern town of Caerleon in Gwent, is the Isca Silurum (or Isca Augusta) legionary fortress which had a standard, playing-card outline measuring 1,600 by 1,350 feet (c.490×410 metres) and encloses an area within the defences of some 50 acres (21ha), easily large enough to house a fully-manned legion of between five and six thousand men. The defences of the fortress are aligned towards the north-west, which implies that the most significant threat was expected to come from that quarter.

The original Flavian timber fortress was built sometime between 70AD to 80, which may place the foundation during the campaigns of governor Sextus Julius Frontinus in 74-75. It was certainly built by the men of Legio II Augusta, who continued to garrison the fortress until the mid-fourth century. An inscription of Trajan gives us a fairly precise dating for the replacement of the fortress walls to 99/100AD, when the original earth and timber ramparts of the fortress were strengthened by the addition of a stone revetment at the front. Defences of this “composite” rampart consisted of a stone wall 5 to 5½ feet thick, backed by a clay bank and fronted by a single ditch.

Between 140AD and 200 occupation evidence is slight, and it has been suggested that most of Legio II Augusta was away in Scotland during this period. The fortress was damaged c.196/7, but by the turn of the third century the legion was evidently back in residence, an inscription records repairs made c.197-211 and another records that the barracks were rebuilt in stone during 259. The coin sequence in the fortress stops in 296, coincident with the period when the legionary fortress at York was rebuilt, and it seems that Caerleon was abandoned at this time, the Legion perhaps moving for a short while to garrison the Coastal Fortress at Cardiff – which had just been rebuilt – before being relocated to Rutupiae on the coast of Cantium.

During excavations at Caerleon over the years a number of animal bones have been uncovered, including those of domesticated Ox, Sheep, Goat, and Pig, also game animals such as Red Deer, Roe Deer, Boar and Hare, and even those of Fox and Wolf; the latter animals very likely being hunted and killed for sport and as a means of pest control. In addition, the soldiers’ diet was supplemented by seawater molluscs including Oyster, Mussel, Limpet and Cockle.

The Builders of the Legionary Fortress

Stamped Tiles from Caerleon

Classical references to Isca Augusta (Caeleon)

The Roman name of the Caerleon fortress occurs in three separate itinera within the late-second century list of imperial road-routes known as the Antonine Itinerary, serving as a terminus on two of these routes.

• Iter XII: “the route from Muridunum to Viroconium“, Caerleon appears as Iscae the home of Legio Secunda Augusta, some twenty-seven miles from Bomium (nr. Bridgend, Mid Glamorgan) and nine miles from Burrium (Usk, Gwent).
• Iter XIII: “the route from Isca to Calleva, one-hundred and nine thousand paces”; a road journey which again starts off with the nine mile road to Burrium (Usk, Gwent), then via Blestium (Monmouth, Gwent) a further eleven miles further along the north bank of the Severn Estuary.
• Iter XIV: “an alternative route from Isca to Calleva, one-hundred and three thousand paces”, begins with a nine mile road trip to the civitas capital Venta Silurum (Caerwent, Gwent), followed by a fourteen mile journey across the Bristol Channel to Abona (Sea Mills, Avon).

The only other classical geography which mentions the Caerleon fort is the Ravenna Cosmology of the seventh century, where the name Isca Augusta (R&C#52) occurs between the entry for Bannio (Abergavenny, Gwent) and the unidentified station Albinumno.

The modern name for the fortress of the Second Legion Augusta, Caerleon, is an amalgam of the British word *caer/gaer ‘camp, fort’, and the Latin legionis ‘of the legion’. Gildas (x.2) mentions two Christian martyrs, namely Aaron and Julius, who were described as Legionum urbis cives ‘citizens of the Legionary town’ (i.e. Caerleon).

The Epigraphy of Isca Silurum

There are eighty-five inscribed stones recorded in the RIB for Caerleon, including thirty-two tombstones, twenty-three centurial and cohort stones, fourteen altars and votive stones, and nine dateable inscriptions.

The Dateable Inscriptions from Isca Silurum

Legio Secundae Augusta – The Second Augustan Legion

There are at least seventeen stones which attest the presence of Legio II Augusta at Caerleon, there is a dedicatory inscription to Mithras (RIB 322), an altar to Regina (RIB 324), five building inscriptions (RIB 326/7, 330/1, 334; vide supra), dating from the reign of Trajan (99/100AD) to that of Valerian and Gallienus (255-260AD), there are also nine tombstones of soldiers (RIB 357, 359-361, 363 & 365-368; vide infra) and another possible funerary inscription (RIB 385) attributable to men of the Second Legion including a damaged testament of a signifer of the legion (RIB 367; not shown).

The Gods of Roman Caerleon

Iupitter

Restoration of a Temple to Iupitter Optimus Maximus During the Reign of Marcus Aurelius and Commodus

1. Imperator Caesar Marcus Aurelius Antoninus Augustus and his warped son Imperator Caesar Lucius Aurelius Commodus Augustus. Marcus Aurelius (‘the philosopher’) had been adopted at the age of sixteen by Antoninus Pius in February 138 along with the like-named seven year-old son of his first chosen successor Lucius Ceionius Commodus. Marcus and Lucius Verus (as he was then known), became joint emperors upon Pius’ death of natural causes in March 161, and ruled together without rancour until Verus’ death after suffering a stroke in February 169. Marcus had elevated his own five year-old son Commodus to the rank of Caesar in 166, and he was made joint Augustus in 177. After becoming sole ruler on his father’s death of natural causes in March 180, he was strangled at Rome in December 192 after spending a depraved twelve years as head of the Roman State.

Fortuna

Other Altarstones and Votive Objects to the Gods

Altar to the Numinibus Augustorum

Altarstones Dedicated to Unknown Gods

The Military Amphitheatre

A large amphitheatre built c.80AD could hold six thousand people within its wooden superstructure, and was probably used for parades, displays and exercises by the garrison of the fortress as well as for the usual gladiatorial entertainments. This (Period I) building was destroyed by fire in the early-second century, and the second (Period II) building erected c.138AD was destroyed around sixty years later c.196/7. It was rebuilt for the third and last time during the campaigns of Severus and Caracalla in Britain c.197-211. The Period III building finally fell into disuse around the middle of the fourth century at the same time that the Caerleon fortress was evacuated. The latest coin from the site is that of Valens (364-378AD).

Beside the River Usk was a massive quay which could accomodate ships with a draught of up to five feet (1.6 metres) at high tide. Nearby, the large baths complex with a swimming pool was still in use in c.345AD when final rebuilding took place. Repairs to the local road network outside the fortress was last carried out c.301-306.

Building Inscription Recording the Govenorship of Desticius Juba

1. Imperator Caesar Publius Licinius Valerianus Pius Felix Invictus Augustus (Valerian) and his elder son Imperator Caesar Publius Licinius Egnatius Gallienus Pius Felix Invictus Augustus (Gallienus) were joint emperors from October 253AD until Valerian’s death in June 260, whereupon Galleinus became sole emperor. Valerians younger son, also named Publius Licinius Valerianus, was given the rank of Caesar in 256 and died early in 258; the stone must date somewhere in this latter period.
2. Governor Desticius Juba administered Britain between 256AD and 258.

A Selection of Tombstones from Roman Caerleon

References for Isca Silvrvmcastra Legionis

• The Romans in Britain An anthology of Inscriptions by A.R. Burn (Oxford 1932);
• The Roman Inscriptions of Britain by R.G. Collingwood and R.P. Wright (Oxford 1965);
• Britannia i (1970) pp.272/3 & p.305 no.1; The Roman Military Diet by R.W. Davies, in Britannia ii (1971) pp.122-142;
• Britannia viii (1977) pp.429-30 no.16; De Exidio Britonum by Gildas, translated by Michael Winterbottom (Phillimore, London, 1978);
• The Roman Imperial Army by Graham Webster (Constable, London, 1979);
• Chronology of the Ancient World by E.J. Bickerman (Thames & Hudson, London, 1980);
• Chronicle of the Roman Emperors by Chris Scarre (Thames & Hudson, London, 1995); 

Roman Roads near Isca Silvrvmcastra Legionis

E (3) to Bvlmore (Coed-y-Caerau, Gwent) Itinera XII/XIII: N (6) to Bvrrivm (Usk, Gwent) SW (13) to Cardiff (South Glamorgan)