How have migration, birth rates, and conversion influenced Muslim population changes across UK cities since 2011?
Executive summary
Between 2011 and 2021 the Muslim population in England and Wales rose from roughly 2.7–2.8 million to about 4 million, an increase of roughly 1.2 million, making Muslims the fastest‑growing faith group and about 6% of the population [1] [2]. Researchers and polling bodies attribute that growth mainly to two structural factors — migration and higher birth rates relative to the non‑Muslim population — while conversion plays only a minor documented role [3] [4].
1. Migration: the headline driver but not the whole story
Demographers repeatedly single out migration as a major source of Muslim population growth in Europe and the UK: Pew’s Europe analysis finds that roughly 60% of Muslim population growth in Europe between 2010 and 2016 came from net migration, and it lists migration alongside births as a core driver of the increase [3]. UK reporting and community analyses frame the 2011→2021 rise (about +1.2 million Muslims) in part as the result of ongoing immigration from South Asia, Africa and the Middle East and higher settlement and subsequent births among earlier migrants [5] [1]. Some commentators use this to argue rapid, immigration‑led change; fact‑checks and official local breakdowns emphasize that growth is uneven and that no major UK city became majority Muslim between censuses [6].
2. Fertility: younger profile and higher birth rates amplify growth
Academic and policy sources show Muslim populations in Western Europe remain younger and typically have higher fertility rates than non‑Muslim populations, which yields natural increase even absent migration [3]. Past UK fertility studies document a substantial gap between foreign‑born Muslim women and UK‑born Muslim women, and they warn that fertility among UK‑born Muslims falls toward national norms over time — meaning births have driven recent growth but the gap narrows with generational change [4]. European work estimates that even without further migration, higher Muslim fertility would still raise Muslim population shares modestly [3].
3. Conversion and switching: present but quantitatively small
Available European estimates find net religious switching away from Islam exceeded switching into Islam by tens of thousands over recent years, making conversion a minor factor compared with births and migration [3]. The Pew study quantifies that religious switching produced only a small loss (about 160,000 across Europe during 2010–2016) relative to the millions added by births and migration [3]. Specific UK accounts in the provided sources do not offer detailed city‑level conversion data; available sources do not mention substantial conversion gains driving city growth [3] [7].
4. City‑level variation: hotspots, not universals
Multiple sources stress that Muslim growth is concentrated in particular local authorities and neighbourhoods rather than turning whole major cities into Muslim majorities. Community reports note high concentrations in some districts and that in places like Bradford and parts of the Midlands a majority of Muslims are now British‑born — showing local maturity of communities — but fact‑checks of political claims warn that no large UK city is majority Muslim on 2021 census figures [2] [6]. The Muslim Council of Britain’s census summary underlines internal diversity and uneven geography: growth is strong but local outcomes vary significantly [8].
5. Projections and generational dynamics: growth that could slow
Longer‑range projections cited in the sources show outcomes are sensitive to migration scenarios and fertility convergence. Pew and UK fertility literature argue that if migration slows and UK‑born Muslim fertility continues to converge toward national levels, growth rates will moderate — births will still add to totals but at a diminishing margin compared with earlier decades [3] [4]. Some media and partisan pieces extrapolate dramatic outcomes; fact‑checks and demographers urge caution because identification and fertility change over generations [7] [6].
6. Political narratives and misinformation risks
Several supplied items demonstrate competing frames: community and policy reports present data on growth and needs [8] [1], while partisan outlets and alarmist commentaries cast the same statistics as “Islamization” or evidence of civic takeover [7] [9]. Independent fact‑checks counter exaggerated claims — for example, that entire cities have “become Muslim” — using 2021 census data [6]. Readers should treat sensational narratives skeptically and rely on census and demographic research for scale and mechanism [6] [3].
7. What the sources do not resolve
Available sources quantify national‑level contributions from migration and births and point to small net effects from conversion across Europe, but they do not provide a comprehensive city‑by‑city decomposition (migration vs births vs conversion) for every locality since 2011. Detailed municipal breakdowns and cohort‑by‑cohort fertility trends in the 2011–2021 decade are not found in the provided reporting (available sources do not mention city‑level decompositions beyond high‑concentration districts) [8] [6].
Takeaway: national census and demographic research agree the UK’s Muslim population rose substantially between 2011 and 2021, driven primarily by migration and higher birth rates; conversion played a minor role. Local impacts differ sharply by place, and political claims that whole cities have “become Muslim” are contradicted by official data [1] [3] [6].