Romans & the coming of Christianitytop
The Romans invasion of Britain in 43 AD brought new influences, and their own gods were combined with native British gods to produce religious hybrids. It also paved the way for a new religion which eventually overpowered the old pagan ways.
The old Druidic order was smashed in 60 AD when its stronghold of Anglesey was invaded by the Roman army. The Druids were the religious officials of the native Britons and they appear to have been the prominent force in fermenting anti-Roman sentiment. The invasion of Anglesey is an explicit acknowledgement of the threat they posed to Roman rule.
Druidism was a religion which may have originated in Britain. In Welsh the word for Druid is Derwydd, which is closely related to the Welsh for oak tree - derwen. And Welsh is a language directly descended from the Brythonic language spoken by the Britons at the time of the Roman conquest.
Julius Caesar noted that the Druids worshipped in oak groves, and according to the historian Tacitus, one of the first things the Roman invaders of Anglesey did was to cut down the many oak groves they found dotted all over the island.
Although Druidic political power was destroyed, worship of the native gods continued. The Roman attitude to religion appears to have been pragmatic - if it didn't threaten the Roman presence it was tolerated. Also they appear to have believed that it wasn't worth risking incurring the wrath of the native gods, for they would only experience bad fortune during their stay in this foreign land. So they got around it by trying to have the best of both worlds by pairing off their Roman gods with their British equivalents, and erecting joint shrines.
One of the most famous in Britain is to be found at the old Roman baths at Bath. The Romans built their shrine around the hot springs there in 54 AD, on the site of a much earlier temple built by the Britons. The original native goddess was named Sul and she was combined with her Roman equivalent Minerva to create the 'composite deity' Sulis Minerva.
In Wales an example of a 'composite deity' was found in temple dedicated to Mars-Oculus at Caerwent, and a stone head dating from around 300 AD found at Caerleon suggests that native British beliefs continued without having to combine with Roman practices.
Folk memories of these ancient British gods persist to the present day in the form of myths and legends, with the finest example in Wales being the Mabinogi. This collection of tales is thought to have been ancient by the time it was written down in the mid-eleventh century. Some believe it is the closest we can get to the magical world of the ancient Britons.
Around the same time as the stone head was being made in the early fourth century, two men named Aaron and Julius were executed in the very same town of Caerleon for following a proscribed religion. It is not known how many shared their fate. But within a hundred years this persecuted faith became the official religion of the Roman empire, and over time Aaron and Julius were acknowledged as the first Welsh Christian martyrs.