This book, a study of warfare in the emirates that constituted the Sokoto Caliphate in nineteenth-century northern Nigeria, was originally prepared as a doctoral thesis at Northwestern University (1970). Since then it has been revised by adding an introductory essay on the evolution of Sudanic warfare; deleting a short chapter on Islamic military practices, and distributing much of that material throughout the book; and incorporating the results of more recent research.

Regrettably, this work went to press without the benefit of research in Nigeria. Three times between 1969 and 1973 I had planned for such research, but in each instance unforeseen problems precluded its fruition. Fortunately the abundance of other accessible materials permitted the writing of a book of this nature.

Grateful acknowledgments are due to many persons. Ivor Wilks encouraged my early research into Sudanic warfare and suggested several fruitful areas of inquiry. Previous drafts of this work benefited from the comments and criticism of Margaret Priestley Bax, Paul J. Bohannan, Ronald Cohen, R. Ann Dunbar, A. H. M. Kirk-Greene, D. Murray Last, Nehemia Levtzion, Paul Lovejoy, and D. J. M. Muffett. I am especially thankful to Victor N. Low for providing me with military data on Hadejia, Katagum, and Gombe; and to M. G. Smith, who made available to me his voluminous fieldnotes and unpublished manuscripts on several emirates. The Council for Intersocietal Studies at Northwestern and the Naval Academy Research Council supported part of the research. Last but not least, Colin Jones of Cambridge University Press is to be commended for his extraordinary patience and understanding.