This book is a study of the early history of the lbadiyya in North Africa, a "moderate" movement among the Kharijis which from its base in Basra gradually spread among the Berbers of the Maghrib in the 750s. The Berbers found in this new religious allegiance an attractive ideology with which to rebel against the central caliphate. An Ibadi imamate, headed by the Rustamid dynasty, was founded in Tahart in 160 or 162/777 or 779 and lasted until 296/909, when it fell to the Fatimids. The book is divided into seven chapters, an introduction and a conclusion. After a brief introduction to the lbadiyya and a survey of the Ibadi sources, the successive chapters examine the nature and ideological underpinnings of the lbadi imamate and its consolidation in North Africa, the economic bases of the lbadi policy, some evidence of Christian support for (even influence on) the Ibadiyya, the tribal alliances of the Ibadis, and finally, the coune of lbadism after the fill of the Rustamids in 296/909.