The Caerleon legionary fort, called Isca in Roman times, was created around 75 AD. Its construction was probably linked to the campaigns of the governor of Britain, Julius Frontinus, against the Celtic tribe of the Silurians. The fort was the seat of the 2nd Legion of Augustus, numbering over 500 men. The site of the fortress was chosen because of its location on the gently rising terrain adjacent to the Usk River, which was accessible to sea-going vessels, and close to the routes between Wroxeter, Gloucester and Carmarthen. The fortifications were used by the legionnaires of 2nd Augusta until about 300 AD, after which the fort was partly still inhabited, although it is unknown whether by civilians or by military units.
In the Middle Ages, Caerleon was one of the administrative centers of the Kingdom of Gwent. In the Roman fort a parish church was built, and a Norman motte and bailey castle. During the Welsh-Norman battles, in 1171 Iorwerth ab Owain and his two sons destroyed the town and burnt the castle. In 1217, both the castle and the settlement were occupied by Wilhelm Marshall, who rebuilt the feudal stronghold. The remains of many ancient Roman buildings have probably been preserved so far to some extent, but were then probably destroyed in order to obtain building materials.
Fort occupied an area of 50 acres, and its earliest fortifications consisted of peat-clay ramparts crowned with timber fortifications. The fortifications were established on a rectangular plan with an entrance gate in the middle of each side. The fortifications were reinforced by timber towers flanking all gates and single timber towers arranged at equal intervals in the perimeter of the fortress walls. The outer defense zone was 8 meters wide and 2.5 meters deep ditch, circling the whole fort. Reinforced with oak stakes, the vertical-walled rampart was 5.5 meters wide and up to 3 meters high. On the inside of the embankment there was a road that allowed legionaries to quickly access every threatened fragment.
At the beginning of the second century AD, fortifications have been rebuilt into stone. The outer part of the embankment received a stone wall 1.5 meters thick, and the gates were reinforced by twin stone towers. Other timber towers were also replaced by a series of stone towers.
The internal layout of the fortress was consistent with the standard plan of the legionary fort: from the east to the west, the way via principalis ran, and from the north to the south via praetoria. In addition, there was a network of other smaller, perpendicular and parallel roads connecting various areas of the fort. The earliest buildings were probably built of wood, later replaced with a stone. In the center there was the headquarter, behind which the legate residence was located. On both sides there are workshops designed for iron processing on an industrial scale. The legion barracks clung to the northern and southern sides of the fort. A single building housed a centuria (80 men), with ten groups of eight men sharing two rooms. The smaller of the two rooms was used as a warehouse, the larger room served as a bedroom. At the end of each block of barracks was the centurion residence, which also included apartments for junior officers and offices of officials. The latrine block was located north of the barracks, directly at the defensive rampart. A number of ovens and kitchens were located on the inner side of the western part of the fortifications, separated from the barracks by the via sangularis route.
On the south side via principalis there were baths. They were one of the first buildings built of stone and are dated to the 75 AD. It was an enormous complex comprising a large, open courtyard with a swimming pool and a huge number of buildings with bathtubs and an exercise room. On both sides of the bathhouse complex, facing the via principlais, there were houses for tribunes and other senior officers. In the south – western corner of the fortress, behind the houses of the tribunes there were three granaries and a large building with a courtyard, which served as a warehouse. Excavations revealed that it was used to store military equipment. On the east side of the bath complex, the hospital was most likely identified, while further legionnaires barracks were located in the south, on both sides via preatoria. To the west of the fort, just outside its fortifications, there was an amphitheater. It was built of earth and built-in with stone, the upper parts were probably timber. The amphitheater could accommodate up to 6,000 people.
Until today, Caerleon has preserved many elements of the ancient Isca fort. The amphitheater survived in the best condition, even now it is use for mass outdoor events, staging and historical reconstructions. Admission to its area, with the exception of special events, is free. To the north-west of it you can see relics of legionary barracks, unveiled during archaeological research. In the town center there is the Museum of Roman Baths with foundations of buildings, mosaics and reconstruction of the pool. The museum is run by Cadw, so the opening times are exactly the same as in the nearby National Museum of the Roman Legion. There is an excellent exposition of artifacts found in the area, as well as reconstruction of the legionaries quarters. Like other national museums and galleries in Wales, access to it is free. In Caerleon, fragments of defensive walls on the south side have also been preserved.
Website gatehouse-gazetteer.info, Caerleon Town Walls.
Website castlesfortsbattles.co.uk, Caerleon roman fort.