CAERLEON, a market-town, in the parish of Llangattock, union of Newport, Caerleon division and hundred of Usk, county of Monmouth, 20½ miles (S. W.) from Monmouth, and 151½ (W.) from London; containing 1174 inhabitants. This place, called by the Britons Caerleon, "city of the legion," or, according to some, Caerllian, "city of the waters," was the Isca Silurum of the Romans, in the time of Claudius, whose second legion, being recalled from Germany, was stationed here under the command of Vespasian. It became the metropolis of that division of the island called Britannia Secunda, and one of the chief cities of the Romans, who fortified it with strong walls three miles in circuit, inclosing a quadrilateral area measuring 530 yards by 460. They erected temples, an amphitheatre, baths, aqueducts, and splendid dwellings of various descriptions, the magnificent remains of which, in the twelfth century, are described by Giraldus Cambrensis, as emulating the grandeur of Rome itself. In the reign of Domitian, St. Julian and St. Aaron preached the doctrine of Christianity in this part of Britain, and suffered martyrdom here; but after the final submission of the Britons to the Roman power, Caerleon became, under the auspices of Antoninus, the seat of learning and devotion. Two Christian churches were erected in honour of the martyrs Julian and Aaron, to which a nunnery, and a priory of Cistercian canons, were annexed respectively; also a third church, to which was added a monastery that afterwards became the metropolitan see of Wales, of which Dubricius, the great opponent of the Pelagian heresy, was the first archbishop. Under his successors the see continued to flourish to such an extent, that, at the time of the Saxon invasion, its college is said to have contained, among other students, not less than 200 who were well skilled in geography and astronomy; it was afterwards translated to Menevia by St. David, and has since that time been known as the see of St. David's. Some small remains of the monastery still exist. The castle was probably built about the time of the Conquest; but no mention of it occurs till the year 1171, when Henry II. seized the town, and deposed Iorwerth ab Owain, lord of Gwent, who, in 1173, retook it after a vigorous defence, and restored it to the Welsh. After repeated sieges it was retained by Llewelyn ab Iorwerth till the reign of Edward I., when, upon the overthrow of the independence of the Welsh, the town fell into neglect, and the castle into decay. The remains of the castle are inconsiderable.
The town is pleasantly situated on a gentle acclivity on the bank of the river Usk, over which is a handsome stone bridge of modern erection, and consists of two streets indifferently paved and lighted; the houses are mostly old and irregularly built, and are fast hastening to decay. Some fragments of the ancient wall still remain and bear testimony to the former extent and importance of the town. The trade consists principally in the manufacture and sale of tin plates and iron, for which there are two large establishments; the articles are conveyed to Newport by the river, in vessels of small burthen. The market is on Thursday; and fairs are held on July 31st and October 2nd, the latter being a large fair for horses. The market-house is a dilapidated edifice, supported on four massive pillars of the Tuscan order, which are supposed to have belonged to some Roman structure, two bases of similar dimensions and character having been dug up near the walls. The county magistrates hold a petty-session once a fortnight. There are places of worship for Baptists, Independents, and Wesleyans; and a free school for 25 boys and 25 girls, founded and endowed in 1724, by Charles Williams, Esq. Several remains of the Roman station are still visible, and numerous minor relics have been discovered, consisting of parts of columns, altars, tessellated pavements, coins, urns, a statue of Jupiter, portions of the baths, &c. To the north of the town is an extensive quadrilateral encampment, with seven smaller camps near it; and on the banks of the Usk are considerable remains of the amphitheatre, called by the inhabitants King Arthur's Round Table. St. Amphibalus, tutor of the proto-martyr St. Albanus; and the martyrs St. Julian and St. Aaron, were born at this place. The renowned King Arthur is stated to have been interred here.