This book is the result of almost thirty years of fieldwork and travels in Africa and beyond, and of reading and teaching the history and development of African Muslim societies to students at the universities of Bayreuth (Germany), Bamberg (Germany), Vienna (Austria), Helsinki (Finland), Gottingen (Germany), and Florida (Gainesville). This work in the field resulted in three monographs on Muslim movements of reform in northern Nigeria (1997), Senegal (2001) and Zanzibar (2009). A further monograph on the history of Muslim societies in sub-Saharan Africa (2013) brought me into the twentieth century, and the present volume will round up my work on the dynamics of Islamic reform in sub-Saharan Africa.

My work on Muslim societies in sub-Saharan Africa started in 1981 in the context of a first field trip to Senegal, where I worked in a farmers’ cooperative in Bamba Thialene. The farmers happened to be Muslim, yet Islam was so much a part of their everyday life that I did not even realise that I was naturally living in a Muslim community. Islam became a theme only when I moved on to Dakar, Senegal's capital and largest city, and was then confronted with the fact that Islam could indeed become a vehicle of political debates, as well as, of course, a platform for the mobilisation of hundreds of thousands of followers in the guise of the Murīdiyya or Tijāniyya Sufi orders. My acquaintance with Muslims deepened in the course of fieldwork in northern Nigeria (mostly Kano, but also Sokoto, Jos, Kaduna, Maiduguri and Zaria) between 1986 and 1988. In northern Nigeria, I enjoyed integration into the zāwiya of Nasiru Kabara in Kano, but also came in contact with outspoken representatives of Nigeria's Salafi-oriented movement of reform, such as Abubakar Gumi, Ismaila Idris and Ibrāhīm Sulaimān.