King Cassivellaunus led the resistance to Julius Caesar's first expedition to Britain in 54 BC by the Catuvellauni, north of the Thames and west of the Trinovantes. Tasciovanus was the first king to mint coins at Verlamion (now St. Albans) ca. 20 BC. He conquered the Trinovantes as his coins, ca. 15-10 BC, were minted in their capital Camulodunum (now Colchester). After a retreat, possibly under pressure from Rome, Camulodunum was retaken, perhaps by his son Cunobelinus, who succeeded him ca AD 9 and ruled for about thirty years.
Cunobelinus's name survived into British legend, as in Shakespeare's play Cymbeline. Geoffrey of Monmouth says he was brought up at the court of Augustus and willingly paid tribute to Rome. increasing trade and diplomatic links with it. Cymbeline staved off the Roman invasion of Britain by Emperor Caligula with support of anti-Roman Druids and exiled fighters from Gaul. Of his three sons Suetonius says Adminius of Kent was exiled by his father by AD 40, prompting the emperor Caligula's abortive invasion of Britain. Of two sons named by Dio Cassius, Togodumnus and Caratacus, Caratacus's coins suggest he seized Atrebates' lands, but exile of their king, Verica, prompted Claudius to launch a third Roman invasion, led by Aulus Plautius, in AD 43. Dio says that by this stage Cunobelinus was dead, and Togodumnus and Caratacus led resistance to the invasion in Kent, but were defeated by Plautius. Plautius sent for the emperor Claudius, who led the final advance to Camulodunum, which became center to a new Roman province. Caractacus continued to fight the Romans in Wales and elsewhere, before being captured and sent to Rome, where he was much admired. Shakespeare is clearly fascinated by the fact that the British held off attacks by the mighty forces of Imperial Rome for almost a century, establishing a formidable identity which continued to surface after nominal conquest as with the devastating revolt of the Iceni under Boudica/Boadicea and the creation of a temporary Northern Empire under Postumus.
[Data courtesy of the Yorck Project, under Creative Commons Attribution-Share- Alike License (Wikipedia)]