Aside from the many Roman-related discoveries at sites along the southern coast, Roman archaeological remains in Wales consist almost entirely of military roads and fortifications.
[2] Archaeologists generally agree that the British Isles were mainly inhabited by speakers of Celtic languages (Celts) before the Roman invasion, organized into many tribes.
[5] Modern scholars theorize that Wales before the Roman conquest was similar to the rest of Iron Age Britain; however, this is still debated due to the sparsity of evidence.
[7] Archaeological assemblages such as the Wilburton complex suggest that there was trade throughout all of Britain including Wales, connecting with Ireland and Northern France.
In Wales the known tribes (the list may be incomplete) included the Ordovices and Deceangli in the north, and the Silures and Demetae in the south.
Archaeology combined with ancient Greek and Roman accounts have shown that there was exploitation of natural resources, such as copper, gold, tin, lead and silver at multiple locations in Britain, including in Wales.
[4] This is evidenced by the archaeological record, which finds vexillation fortresses (small Roman forts) at the time of Nero's accession.
[4] After a short period of relative inaction, Quintus Veranius became governor of Britain and decided it was time to conquer the rest of the British Isles.
[11] However, this victory was short-lived, and a massive rebellion in the province of Britain led by Boudica erupted in the east and interrupted the consolidation of Wales.
[14] The production of goods for trade and export in Roman Britain was concentrated in the south and east, with virtually none situated in Wales.
Clusters of tileries, both large and small, were at first operated by the Roman military to meet their own needs, and so there were temporary sites wherever the army went and could find suitable soil.
It is possible that Roman estates in the area survived as recognisable units into the eighth century: the kingdom of Gwent is likely to have been founded by direct descendants of the (Romanised) Silurian ruling class [16]' The best indicators of Romanising acculturation is the presence of urban sites (areas with towns, coloniae, and tribal civitates) and villas in the countryside.
[18] In the southwestern homeland of the Demetae, several sites have been classified as villas in the past,[19] but excavation of these and examination of sites as yet unexcavated suggest that they are pre-Roman family homesteads, sometimes updated through Roman technology (such as stone masonry), but having a native character quite different from the true Roman-derived villas that are found to the east, such as in Oxfordshire.
The Roman fort complex at Tomen y Mur near the coast of northwestern Wales has produced more inscriptions than either Segontium (near modern Caernarfon) or Noviomagus Reginorum (Chichester).
[21] In areas of civil control, such as the territories of a civitas, the fortification and occupation of hill forts was banned as a matter of Roman policy.
[23] It is fortunate for Rome's reputation that Tacitus described the druids as horrible, else it would be a story of the Roman massacre of defenceless, unarmed men and women.
Any native religious sites would have been constructed of wood that has not survived and so are difficult to locate anywhere in Britain, let alone in mountainous, forest-covered Wales.
[26] In the De Excidio et Conquestu Britanniae, written c. 540, Gildas provides a story of the martyrdom of Saint Alban at Verulamium, and of Julius and Aaron at Legionum Urbis, the 'City of the Legion', saying that this occurred during a persecution of Christians at a time when 'decrees' against them were issued.
[31] Political control finally collapsed, and a number of alien tribes then took advantage of the situation, raiding widely throughout the island, joined by Roman soldiers who had deserted and by elements of the native Britons.
It was at this time[33] that Wales received an infusion of settlers from southern Ireland, the Uí Liatháin, Laigin, and possibly Déisi,[34][35][36] the last no longer seen as certain, with only the first two verified by reliable sources and place-name evidence.
The Irish were concentrated along the southern and western coasts, in Anglesey and Gwynedd (excepting the cantrefi of Arfon and Arllechwedd), and in the territory of the Demetae.
The circumstances of their arrival are unknown, and theories include categorising them as "raiders", as "invaders" who established a hegemony, and as "foederati" invited by the Romans.
Tradition holds that Roman customs held on for several years in southern Wales, lasting into the late 5th and early 6th century, and that is true in part.
The entire region of southwestern Wales had been settled by Irish newcomers in the late 4th century, and it seems far-fetched to suggest that they were ever fully Romanised.
This is the last date for any evidence of a Roman military presence in Wales, the western Pennines, and Deva (i.e., the entire non-Romanised region of Britain south of Hadrian's Wall).
[42] In the De Excidio et Conquestu Britanniae written c. 540, Gildas says that Maximus left Britain not only with all of its Roman troops, but also with all of its armed bands, governors, and the flower of its youth, never to return.
After he became emperor of the Western Roman Empire, Maximus returned to Britain to campaign against the Picts and Scots (i.e., Irish), probably in support of Rome's long-standing allies the Damnonii, Votadini, and Novantae (all in modern Scotland).
While there he likely made similar arrangements for a formal transfer of authority to local chiefs: the later rulers of Galloway, home to the Novantae, claimed Maximus as the founder of their line, as did the Welsh kings.
Gwyn A. Williams argues that even at the time of the construction of Offa's Dyke (that divided Wales from medieval England) the people to its west saw themselves as "Roman", citing the number of Latin inscriptions still being made into the 8th century.