Within the RBO WebSite, the convention dictated by the excellent publication from the Ordnance Survey, The Historical Map and Guide - Roman Britain, is followed throughout. The Ordnance Survey separates the settlements of Roman Britain into several types:
Aquae Sulis (Bath, Avon)
Many of the Romano-British settlements in Britain began life as small civilian communities in the vicinity of a Roman auxiliary fort. The soldiers' regular salaries attracted the attentions of merchants offering all kinds of merchandise and every sort of service which would tempt a Roman soldier to reasonably part with his money. Apart from the obvious ale-houses, bakeries and brothels, there would be tailors, cobblers, smiths and other tradesmen.
Even though it was not permitted for any of the common Roman soldiery to be legally married, plenty of illicit affiliations were constantly going on - such is the nature of man. It is very probable, therefore, that a substantial proportion of each of these initial settlements would be composed of the soldiers' dependants.
These small settlements were termed vici, as they tended to develop along either side of the street or vicus leading from the main gate of the parent fort, with their frontages opening onto this main road. A settlement of this nature established outside a large fortress, was termed a canabae from the type of four-posted hut (Latin canaba) which was prevalent. It seems that both of these types of Romano-British settlement were under some degree of military jurisdiction, due to their proximity to the local fort or fortress. This military involvement in the local administration very likely lapsed as soon as the garrison moved on. The settlement left behind either survived or declined as local circumstances dictated.
If a fort was garrisoned for a long period of time, or the local natural resources made possible the establishment of substantial local industries, in time, a vicus may develop into a more substantial settlement or town. The presence of local industries and their associated markets increased trade and brought wealth into the area, which attracted more of the civilian population to settle there.
As these settlements became more populous and prosperous, the local governing bodies were able to fund civic building projects such as Fora to encourage general social interaction and market trading, Basilicae for the advancement of local government and the enforcement of civil law, also Bath-houses Temples and Amphitheatres for the entertainment of the masses.
As in Gaul, the Roman government of the province of Britain was broken down into large administrative areas based on the existing territories of the conquered Celtic tribes. This system made use of the established communication links between these tribes and has the fortunate side-effect of preserving the ancient Celtic tribal boundaries, which has substantially helped in our understanding of the inter-tribal relationships in pre-Roman Britain. These administrative sub-divisions of Roman provincial government are known as civitates. A further sub-division of these administrative areas, termed pagi were centred on other towns and major settlements within each tribal canton. These settlements were politically answerable to the local civitas capital.
Most of our information regarding the place-names of Roman Britain has come from five main written sources, three of which contain the names of British Civitas capitals: the Antonine Itinerary, the Ravenna Cosmography and the Peutinger Table. These ancient documents list the names of cantonal capitals with tribal suffixes appended, such as Calleva Atrebatum. In this manner, eleven Romano-British towns are confirmed as civitas capitals in one or more of these documents:
The above list omits several Romano-British towns which are now known to have been tribal administative centres:
The fact that these known cantonal capitals are not listed as such in the major sources proves that these documents are not complete lists of the Roman settlements of Britain, only those that lay along well-established military highways and the primary trade-routes.
Another important ancient source is that of Ptolemy the geographer and astronomer, from whom we learn the names of many of the rivers and coastal areas of Britain, as well as the names of several of the smaller British tribes. The Notitia Dignitarum also adds further details to our overall knowledge.
Further information regarding the physical extent of the territories of the British Celtic tribe is available under the individual RBO WebPage entry for each tribe. Vide British Tribes. An invaluable book on the subject of the Roman settlement of Britain, Town and Country in Roman Britain, by A.L.F. Rivet, is unfortunately out of print but may be available at your local library.