For what it's worth the "Dark Ages" were also predominantly Christian - the Anglo-Saxons had a significant Christian population and the Normans replaced an Anglo-Saxon cathedral in Norwich with their own construction (I may be wrong but I think that the Cathedral in Tombland (from the Anglo-Saxon for open area) needed six Anglo-Saxon churches to be knocked down to allow it to be built). The Vikings were considered Dark Age and they made a healthy living raiding monastaries. Historically Norwich has generally been regarded as one of the leading non-conformist cities in England and consequently has a number of places of worship (such as the Unitarian Octagon chapel) to reflect this. Some would argue that having a significant non-religious population would make Norwich one of the more forward thinking and looking places in the country.
Yeah, it's a funny one. The way nearly every religion presents theism (possibly with the exception of Buddhism) flies in the face of an awful lot of expected scientific theory, yet at the same time, science can't disprove the existence of a God. I think in one of the long religion based GC threads I made the point that the only real gaps in scientific understanding where a god could fit in are the start of the universe and the start of life, and we've got some decent ideas on both. I'm not sure if this is a US or a UK thing, but if enough people reply with the same answer in the 'other' category, it is officially included on the next census, hence Jedi managing it in the past. So, if enough of us put 'Norwich City' next time...
I also heard on the news last night that the Millenium Library is the most heavily used in the country and also had the most books (1.3m) being taken out. Supposendly this is twice as many as the next highest. I don't know if this is linked to the lack of religion? Thinking about it Norwich has an unusaually young population (average age is apparently 34 compared with a national average of 39) and we also have a lot of science institutes and fewer migrants all of which probably tilt the city to having fewer religious people. It could simply be that people here are a bit more open about not being religious. I am not saying religion is a good or bad thing - for every 9/11 there are thousand of faithful, law abiding people doing charitable works. Interestingly Brighton was number 2 in the non-religious list.