British Bangladeshis (Bengali: বিলাতী বাংলাদেশী, romanized: Bilatī Bangladeshī) are people of Bangladeshi origin who have attained citizenship in the United Kingdom, through immigration and historical naturalisation. The term can also refer to their descendants. Bengali Muslims have prominently been migrating to the UK since the 1940s. Migration reached its peak during the 1970s, with most originating from the Sylhet region. The largest concentration live in east London boroughs, such as Tower Hamlets. This large diaspora in London leads people in Sylhet to refer to British Bangladeshis as Londoni (Bengali: লন্ডনী).