of Islamic theology. Their knowledge of various Islamic theological groups has made them the foremost Orientalists in the study of classical Islamic theological history. Their contribution had an immediate impact on modern scholars, and, since the 1980s, scholars have conducted extensive research on Ibāḍī theology and jurisprudence inspired by their work. They proved that the study of the emergence and formation of Islam has been reflected significantly in the Ibāḍī literature which, as a consequence, has become a premier source for this field of study of Islam was inaugurated by John Wansbrough, Michael Cook, Martin Hinds, Patricia Crone, Gerald Hawting, and Andrew Rippin. In contrast, the branch of Oriental studies dealing with Ibāḍī jurisprudence is rather fragmented in its approach to the history and background of Ibāḍī jurisprudence. Thus, it is difficult to make a comprehensive survey of its contribution. We cannot deny that this was because of the limited availability of Ibāḍī works in print. Moreover, this deficiency might have been caused by the fact that, in the first half of 20th century, most Orientalists concentrated on classical Islamic philosophy and theology. To illustrate the contribution of the Orientalists, we should begin with the early articles published by E. Sachau in 1894, e.g., his paper on Abu al-Hasan al-Bisiyawi. Later, Sachau published a paper on Ibāḍīs on the eastern coast of Africa. Schacht’s theories on “The origin of Muhammadian jurisprudence” have greatly influenced the study of Islamic jurisprudence and have induced researchers to examine his views. Undoubtedly, Schacht had a great impact on the reconstruction of the development of Islamic jurisprudence after Ignaz Goldziher’s work “Introduction to Islamic Theology and Law”. Since 1987, the finest work on Ibadi jurisprudence has been produced by Ersilia Francesca in the form of both books and articles. Later on, works by American researchers with an anthropological background on Oman’s politics and economy began to appear in 1967 with Robert Landen and in 1978 with John Peterson, who is known for his extensive writings on the modern history and politics of Oman. Since 1980, Dale Eickelman has published many texts about Oman. In his anthropological writings, he compares Oman with different areas of the Muslim world. His work triggered the emergence of a new generation of American researchers in the field of Oman and Ibāḍī Studies, such as Valerie Hoffman, Mandana Limbert and Adam Gaiser. New developments in the field of Ibāḍī studies were