Isca Dumnoniorum of the legion at Exeter is supported by the discovery of a dolphin antefix (roof fitting) from levels within the military bathhouse dated to about 60. The antefix appears to have been created from the same mould as an example from the legionary fortress at Caerleon—where the legion is known to have been stationed from around 75. (The legion had previously suffered a defeat to the Silures of southern Wales in the year 52.) The legions of Britain were rearranged after Suetonius Paulinus's victory against the Boudiccan rebellion. There was a small subsidiary fort at Topsham. A supply depot along
Isca Augusta legion was needed to repel a potential invasion from the Continent. The stone from Isca may have been used for building defences on the south coast. There may still have been an occasional military presence as late as the early 4th century, but the fortress was probably later taken over by the people of the surrounding vicus. The basilica of the baths was used as a cattle pen. Recent finds suggest Roman occupation of some kind as late as AD 380. According to the Gildas (followed by Bede), Roman Caerleon was the site of two early Christian martyrdoms in Britain,