Shadow of Camelot
The Romans left the city to itself. And while it has not entirely collapsed, it cannot be said to be thriving.
There is a modest amount of trade in the region, mostly among local farmers. Over all this area is slowly melting into the control of Mercia, much to the dismay of some of the older, established descendants of the Roman invaders.
A vague form of Catholicism is observed, but very loosely. The Southwest edges of the city are home to a school of sorcerers that claim to have learned their trade from Merlin. Either way, their proficient use of magic has helped to keep the near-by region safe from Fey creatures.