This book explores the idea of Muslim diaspora in context of Muslim communities in the United Kingdom. It critically looks at the notion of ummah and presents a comprehensive account of South Asian Muslims in London. Employing qualitative research methods and drawing on extensive fieldwork, it delves into the identification and transnational connections of Muslims in Britain. It shows the ways in which religious identity, practices and experiences may instigate diasporas focusing on South Asian Muslims in London -- Indian, Pakistani and Bangladeshi Muslims -- who account for 3.6 per cent of the total population. Further, the inter as well as intra group dynamics and studies how Muslims of different ethnic background settled in the same geo-political context engage with the notion of ummah. The volume will be of great interest to scholars and researchers of religion, especially Islam, politics, British studies and South Asian studies.