This article is devoted to revealing the historical preconditions of the formation of a Muslim Afro-Asian diasporas in Great Britain. Contrary to stereotypical and popular perceptions of Muslims as a monolithic group, one of the most striking aspects of Muslims living in Britain today is their diversity. This is clearly refl ected in the wide range of ethnic backgrounds that they encompass, and is directly related to the fact that Muslim migration to Britain from many different parts of the world has been an important feature of the last 150 years. Chronological frameworks of the article cover the period from the mid-nineteenth century (because the fi rst relatively permanent Muslim populations were established in Cardiff, Liverpool, Manchester, South Shields) to the present moment. The colonial past of the empire in many respects has defi ned ethnic structure of the Muslim community. Process of disintegration of the British colonial empire has led to substantial growth of immigration fl ows. Since the Second World War, Muslims have migrated to Britain in relatively much larger numbers, with the majority coming from South Asia (primarily Pakistan and Bangladesh). In addition, smaller Muslim communities from a variety of regions, including parts of Africa, Malaysia, the Middle East and, more recently, Eastern Europe (primarily Bosnia), have also settled in Britain. The processes which directly affected structure, volume and ethnocultural variety of Muslim Afro-Asian diasporas of the country, are included into a problematics of the article.