Maps in this section include:

The previous chapter ended by showing how marriage continues to decline in popularity across the UK, falling in popularity everywhere, but slightly faster where the population is rapidly becoming younger. Only in the west of Northern Ireland and on two small islands is the crude rate of marriage increasing, and only because there are relatively fewer children (too young to marry) there. The decline in marriage in the UK is largely a reflection of the continued and very long-term decline in the power of the established church. Although the majority of marriages that take place in the UK are now civil ceremonies, the continuation of marriage largely reflects a continuation in practises established by the church. It was the continued decline in the influence of the established church, coupled with lobbying from the other religions of the UK, which lead to the 2001 Census being used to take the first official survey of the religious beliefs of the population held since 1851. Ironically, while the 1851 religious census was concerned with the differing numbers of people practising different forms of Christian belief, in England and Wales in 2001 all the various Christian denominations were amalgamated.

The census showed that Christianity was strong when measured in this way only in a few parts of the North West of England. Large numbers of people in Scotland and Wales clearly now object to being asked their religion through a census. The non-Christian religions were most dominant in the major city regions, London, the Midlands, the Northern conurbation, Glasgow and in Cardiff. Here, too, people were most likely not to state their religion when asked (an option given on the form). In Scotland very high numbers stated they had no religion, similar to the districts with the very highest proportions with no religion in Northern Ireland, and perhaps stating so for similar reasons.

Other than Christianity, no religion holds sway over large groups of the UK population, but people are more likely to tick allegiance to another religion because of adherence, rather than simply because they have once or twice been in a church.

Muslims are in a small minority in every district in the UK. In the three districts with the highest proportions they only number just over a third of the population, just under a quarter and just under a fifth.