The political history of Cunobelin's kingdom from this point until his death around AD 40 can be traced only in its broadest outlines, but it would seem to justify Suetonius' use of the term King of Britain in that Cunobelin came to directly control a substantial part of Southern England, and exerted political and economic influence over an even greater area.

Although one cannot write political history from the changing distribution of inscribed coinage, the common appearance of Cunobelin's coinage in Beds, Cambridgeshire, Northants, Oxon and north Berks (as well as in Essex, Herts and Bucks) and the almost total absence in these same areas of the coinagre of any other monarch or tribe must surely reflect Catuvellauni domination of these areas. That his influence reached still further afield is suggested by the appearance of his coins in Sussex, Hants, Gloucestershire and Norfolk.

His coins are sufficiently common in north Kent for some scholars to suggest that he seized direct control of at least part of thekingdom of the Cantiaci. It is indeed possible that he installed one of his sons, Adminius, in Kent just as one of his brothers, Epaticcus, seems to have been given control of the northern part of the Atrebatic kingdom.

Ironically, Adminius and Epaticcus were to be responsible for bringing about the destruction of Cunobelin's kingdom by the forces of Rome. In AD 39 Adminius fell out with his father and fled to Gaul, where he sought and obtained the help of Gaius Caligula to intervene in British affairs. Although the planned invasion was aborted, Gaius made much of the affair in Rome and revived Roman interest in the possibility of occupying Britain.

Three years later as Catuvellaunian pressure on the remainder of the Atrebatan kingdom increased the Atrebatan king, Verica, fled to Rome and begged the new emperor, Claudius, to intervene on his behalf. The Claudian invasion followed, followed and within twelve months, the kingdom which Tasciovanus and Cunobelin had so skilfully established over a period of fifty years had been swept away by the legions of Rome.

Sources:
Branigan, Keith, The Catuvellauni, 1984, London