Britain

[Briton]

Hi

I was wondering, firstly: since recent genetic and linguistic evidence has shown that the 'celts' were not so much a migration of population but of culture, and that certain 'celtic' cultural aspects may have existed in Britain before their arrival, what were the main gods of the Britons, if anyone knows, before the celts arrived.
Secondly, for those that follow 'Brythonic' paganism, what are the main gods followed around the time paganism was in its heyday in britain, or today, and could you describe them.

Sorry, im new to this!

Yours, Briton