Blestium Blestium ( also Blestio in the Antonine Itinerary ( Iter XIII ) ) was a small fort and iron working centre in the Roman province of Britannia Superior , part of Roman Britain . It has been identified with the site of the later town of Monmouth in south east Wales , located adjoining the confluence of the River Monnow with the River Wye . A plaque on the local bank records its position . History and remains . The reference to " Blestio " in the Antonine Itinerary is the only one made to the settlement in Roman sources . It was located on the road between Caerleon ( ' ) and Silchester ( ' ) , midway between the fort at Usk ( ' ) and the iron making centre at ' , believed to be at Weston under Penyard near Ross - on - Wye . It is suggested that the name may derive from the Greek word βλαστος , meaning " offshoot " . It is now generally accepted that a Neronian or pre - Flavian military fort was established at Monmouth , perhaps before 55 AD , making it the earliest Roman fort in Wales . The fort was probably established , either by Publius Ostorius Scapula or his successor Aulus Didius Gallus , during the first advances of the Romans against the Silures of south east Wales . The invading forces established a series of auxiliary forts along the Monnow valley into mid Wales , as well as advancing towards Usk where they established the fort of " Burrium " . The Silures fought a successful guerrilla war against the Romans for some thirty years before being defeated by the forces led by Sextus Julius Frontinus . The fort at " Blestium " is believed to have housed around 2 , 000 soldiers during the initial campaign , and later to have remained as a small fortlet . Relatively few Roman remains had been found at Monmouth until recently . The first ditch of the fort was discovered by the Monmouth Archaeological Society behind properties on Monnow Street , within Monmouth town centre . Excavations in 2010 in Agincourt Square also uncovered pottery and bones , which appear to confirm the existence of a fort . There is substantial evidence of iron working dating from the Roman period , drawing on local iron ore and charcoal for smelting from local forests . This includes hearths and waste slag , both in the town centre and in the Overmonnow area . Stone buildings associated with 2nd and 3rd century iron working have been excavated near the crossing of the River Monnow . Coins found in the town date mainly from the third and fourth centuries , suggesting continuing civilian settlement . Monmouth Heritage Trail . The Monmouth Heritage Trail includes a blue plaque recording the Roman fort of " Blestium " . This is attached to a late eighteenth - century town house which is now used as the Lloyds TSB bank in Monnow Street . The house was occupied , and probably built , by Philip Meakins Hardwick , who was one of the founders of the Monmouth Picnic Club of local gentlemen responsible for developing the viewpoint and buildings on The Kymin around 1800 . The house became the home of Monmouth ' s town clerk and Viscount Nelson and his entourage were entertained there during their visit to the town on 19 August 1802 . Another notable resident was said to be the architect Philip Fisher who lived at the house whilst designing improvements to the Shire Hall in the 1720s . The building is a Grade II listed building .