The only classical account of Plautius' invasion of Britain is Cassius Dio's History of Rome (book LX, chapter xix), with anectodal references in Suetonius' Claudius (chapter xvii). The best modern book on the subject by far is Graham Webster's The Roman Invasion of Britain (Batsford, London, 1980).
The original bridgehead fortifications at Rutupiae (Richborough, Kent) are well known and enclose an area of about 140 acres (c.57 ha). A military precursor to the civitas of the Cantiaci tribe at Durovernum (Canterbury, Kent) has been postulated but the only evidence which has come to light thus far are the foundations of a number of timber buildings built in Roman military style also a re-cut V-shaped defensive ditch at another location within the bounds of the later walled town. Another fortification is suspected at Durobrivae (Rochester, Kent) at the crossing of the Medway, where the Roman invasion force met its first real opposition and a major battle was fought which lasted two days and claimed the life of the British warlord Togodumnus, the brother of Caratacus. The ditch of a large (c.75 acres, 30.5ha) Claudian camp has been confirmed at Londinium (London, Greater London) near the crossing of the Thames in Fenchurch Street, and it is thought that another camp, similar in size, was positioned further to the west near Hyde Park.
Following the advance through Cantium and the surrender of the British tribes near Caesaromagus (Chelmsford, Essex), a legionary fortress was built by the Twentieth Legion within the Oppidum of the Trinovantes tribe at Camulodunum (Colchester, Essex), which was supplied along the River Colne via a harbour on the estuary at Fingringhoe Wick. With his rear guarded, Plautius then sent his remaining three legions to the task of pacification.
Many British tribes were brought under the yoke of Rome during the four years of this general's tenure in Britain. Many of the Romanised civitas centres of these tribes began life outside the defences of Roman garrison forts built by the legionary troops and occupied by the auxilia, often being sited at the centre of the tribe's territories or within oppida earthworks.
A notable omission from the above list is Calleva Atrebatum (Silchester, Hampshire) the civitas of the Atrebates tribe, who apparently continued to occupy their ancient woodland capital with no trace of a nearby Roman garrison fort.
Plautius was also active in the diplomatic arena during his governorship, installing Adminius as 'client' king of the Cantiaci in Cantium/Kent and recognising Cogidubnus as 'pro-praetorian legate' with authority over the Regnenses tribe of Suffolk and West Sussex. He also brokered treaties with two other major tribes, recognising Cartimandua of the Brigantes in Northern England and Prasutagus of the Iceni in Norfolk as 'clients' of Rome.
|Camulodunum (Colchester, Essex)||TL9925||legionary fortress Legio XX Valeria.|
|Longthorpe, Cambridgeshire||TL1597||vexillation fortress Legio IX Hispana.|
|Lake Farm, Dorset||SY9999||fort, vexillation fortress Legio II Augusta.|
|Alchester, Bicester, Oxfordshire||SP5720||fort, vexillation fortress Legio XIV Gemina.|
|Noviomagus Regnorum (Chichester, West Sussex)||SU8604||vexillation fortress of Legio II Augusta, later civitas capital of the Regnenses.|
|Ratae Coritanorum (Leicester, Leicestershire)||SK5804||probable vexillation fortress of Legio IX Hispana, later civitas capital of the Coritani.|
|Rutupiae (Richborough, Kent)||TR3260||invasion bridgehead and naval base.|
|Fingringhoe Wick, Essex||TM0519||naval base serving legionary fortress at Colchester.|
|Magnus Portus (Bosham Harbour, West Sussex)||SU8003||naval base serving the early fortress at Chichester.|
|Hamworthy, Poole Harbour, Dorset||SZ0090||naval base serving vex. fortress at Lake Farm.|
|Topsham, Devon||SX9688||naval base|
|Caesaromagus (Chelmsford, Essex)||TL7006||fort, later civitas capital of the Trinovantes|
|Canonium (Kelvedon, Essex)||TL8618||fort|
|Stanway, Colchester, Essex||TL9622||fort set in the middle of the British royal enclosure.|
|Combretovium (Baylham House, Suffolk)||TM1152||fort|
|Ixworth, Suffolk||TL9369||fort, possibly named Sitomagus.|
|Durobrivae (Water Newton, Cambridgeshire)||TL1296||fort|
|Great Chesterford, Essex||TL5043||fort|
|Verulamium (St. Albans, Hertfordshire)||TL1307||fort, later civitas capital of the Catuvellauni|
|Shapwick, Dorset||ST9402||fort near the Lake Farm campaign fortress.|
|Dunum (Hod Hill, Dorset)||ST8510||fort in corner of a hillfort of the Durotriges.|
|Charterhouse on Mendip, Avon||ST5056||fort protecting silver workings in the Mendip Hills.|
|Corinium (Cirencester, Gloucestershire)||SP0201||fort, later civitas capital of the Dobunni.|
|Great Casterton, Leicestershire||TF0009||fort|
|Causennae (Ancaster, Lincolnshire)||SK9843||fort|
|Ad Pontem (East Stoke, Nottingham)||SK7550||fort|