[5] Part of this increase can be attributed to the demographic transition seen in most industrialising countries during the Industrial Revolution, as death-rates dropped and birth-rates remained steady.

[9] The main population and industrial areas are in South Wales, including the cities of Cardiff, Swansea and Newport and the nearby valleys, with another significant population in the north-east around Wrexham and Flintshire.According to the 2001 census, 96 per cent of the population was White British, and 2.1 per cent non-white (mainly of British Asian origin).

Welsh Asian and African communities developed mainly through immigration after the Second World War.

[11] In the early 21st century, parts of Wales saw an increased number of immigrants settle from recent EU accession countries such as Poland,[12] though a 2007 study showed a relatively low number of employed immigrant workers from the former Eastern Bloc countries in Wales compared to other regions of the United Kingdom.

[13] The 2001 UK census was criticised in Wales for not offering Welsh as an option to describe respondents' national identity.

[14] Partly to address this concern, the 2011 census asked the question "How would you describe your national identity?".

Respondents were instructed to "tick all that apply" from a list of options that included Welsh.

[20] Just over 1.75 million Americans report themselves to have Welsh ancestry, as did 440,965 Canadians in Canada's 2006 census.

[29] According to the 2011 census 2.2 million (73%) of the usual residents were born in Wales, a reduction of two percent since 2001.

An analysis of the 2011 data by Manchester University's Centre on Dynamics of Ethnicity revealed that:[37] The remainder chose other national identities.

This was a reduction of approximately two per cent compared to 2001, though the method of analysis differed between the two censuses.

In contrast, single people (i.e. those who have never married or been part of a same sex partnership), have increased by 190,000 (6%) in the ten-year period.

[36] Table key Out of all the armed services, the Army has the largest presence in Wales, with over 1,400 personnel based there.