I would like to express my appreciation to those precious people who have been involved in the preparation of this book. First of all, thanks go to Brill for providing me with the opportunity to revise and update the work that was published in “Themes in Islamic Studies”. With remarkable patience, Kathy van Vliet and Patricia Radder handled the problems of a publication that, due to its sheer size and complexity, threatened to go to pieces. The encouragement of the editors of the Handbook of Oriental Studies were quite important in keeping the project going. Stefan Hoffmann and his “Eckpunkt” team in Erfurt arranged for the maps. I am thankful to all those scholars who read various parts of the book, listened to my explanations with endurance and gave highly beneficial comments and rectifications. Those affiliated with the Department of Religious Studies at the University of Erfurt—current and former—have been an invaluable source of inspiration. The list of names is long and many of them have already been named in the first edition of ISA. During the last years, however, my colleagues Christoph Bultmann, Andreas Gotzmann, Vasilios Makrides, Katharina Waldner and Isabella Schwaderer gave me necessary backing whenever needed. I have also highly benefited from students and scholars such as Misbahur Rehman, Muhammad Akram, Neda Saghaee, Muhammad Hussain, Syed Furrukh Shah, Faiza Hussain, Soraya Khodamoradi, Saeed Zarrabi-Zadeh, Yousra Ibrahim, Reka Mate, Reik Kirchhof, Hasnain Bokhari, Thomas Gugler, Moez Khalfaoui, and many others. They all took pains to hear and rehear my ideas and deliberations and also to critically read and make revisions to parts of the manuscript, in spite of their own academic preoccupations and commitments. Many thanks go to Michael Asbury who did a wonderful job in revising and commenting on the manuscript. To all of these colleagues, peers, students and friends I am truly grateful; their expertise and comments were important additions to my own limited knowledge. Bushra took a constant interest in my efforts and stood supportively beside me throughout the different phases of the work. Benjamin and Momin both shared a rather well-tempered approach to my writing desk. How could the book have been finished without their abiding encouragement and love?