This major work analyzes competition between followers of two major world religions for mastery of the east central region of Africa. Bennett meticulously traces the process by which European economic and political rivalry with the Muslim rulers of east central Africa became transformed into a holy war against the Arabs.

Bennett documents these complex relationships through three stages of their development: the first contacts of Arabs, Europeans, and Africans (1800 to 1870s); the peaceful competition of the 1880s; and the downfall of Zanzibar dominions in the last part of the 19th century.