Camulodunum was the capital of the Trinovantes tribe in the years immediately preceeding the Roman invasion of Britain. The settlement is sometimes identified with modern Colchester, but that identification needs to be qualified. The original site was at Gosbeck's Farm, just outside Colchester.

Around the year 5 AD Camulodunum fell to Cunobellinus (Shakespeare's Cymbeline) of the Cattevellauni tribe, who established a new capital covering 12 square miles at Sheepen. When the Romans invaded, this tribal settlement became the site of the capital of all of Roman Britain.

After 49 AD a new colonia was founded for veteran soldiers, and the former legionnary barracks were adapted for civilian use. The city was extended and a new temple built to the God-Emperor Claudius, but the city was levelled in the Boudiccan revolt of 63 AD. It took at least 15 years for Camulodunum to recover from the ravages of Boudicca, by which time London had become the new provincial capital.

Related:
Trinovantes
Boudicca's Revolt
Catevellauni
The Roman invasion

Roman attractions in Britain (places to see tagged with 'Roman')