In the period immediately preceeding the Roman invasion of Britain the Trinovantes tribe occupied the area of Britain now taken up by Essex. The "capital" of the Trinovantes may have been at Colchester (Camulodunum).

There is some suggestion that the Trinovantes rulers may have been "under-kings" of the Catevellauni. The expulsion of a Trinovantes prince by Cassevellaunus of the Catevellauni was the pretext for Caesar's invasion in 55BCE. The Trinovantes saw the Roman invasion as an opportunity to strike back at their northern rivals and they were quick to join with Caesar and strike against the might of the Catevellauni.

After the more permanent Roman invasion under Claudius in 43AD, Colchester became a colonia (49AD), or Roman city of the highest rank. The Trinovantes enjoyed the fruits of cooperation with the Romans until the loss of tribal territory to Roman settlers caused the Trinovantes to join with the Iceni revolt under Boudicca (Boadicea) in 61AD, and the colonia of Camulodunum was burned to the ground.

The Trinovantes vanished from history after the failure of the Boudiccan revolt until medieval romances linked the tribe with the names of the legendary figures Brutus and Corineus, mythical founders of Britain and Cornwall, respectively.

Known and possible kings of the Trinovantes include:

Addedomeros
Dubnovellaunos

NOTE: The name of this tribe is also spelled Trinobates. The names of the British Celtic tribes are those assigned by Roman commentators, and not neccessarily those employed by the Celts themselves.

Related:
Celtic Britain
Roman invasion