works and early Ibāḍī writings. The exploration of Omani literature started only in the mid-1970s, when John Wilkinson and G. Rex Smith published a number of writings on Ibadism in Oman. 20th-century Ibāḍī studies At the beginning of the 20th century, the development of interdisciplinary, historical and philological studies promoted the study of Islamic theology and jurisprudence. The comparisons between different Islamic groups led researchers to write books and articles on heresiography and the history of Islamic theology. In 1902, the German Orientalist, Wellhausen, published his work on the religio-political groups in Islam, concentrating on the Kharijites and Shiites. This remarkable change of paradigm in the study of Ibadism and its history was introduced by the Italian researcher Laura Veccia Vaglieri. A number of her papers deal specifically with Ibadism. However, the most significant study was by the Italian Orientalist, Nallino (1916), who tried to understand the doctrinal affinities between Ibadism and the Mutaziltes. Indeed, Nallino, understood the Mu‘taziltes to be Islamic rationalists; however, Nallino was able to alter the way in which Oriental scholars’ related Islamic theology with classical philosophy. This, in turn, influenced the historical-political perspective on Ibadism, leading to a deeper study of Ibāḍī theology. Nallino was followed by his student, the Italian scholar Roberto Rubinacci, who continued Nallino’s efforts and studied Ibāḍī doctrinal texts (creeds and epistles) which were published between 1949 and 1989. During the 1960s, the British scholar Watt Montgomery published several papers on Islamic theological history which treat of Wāsil b. Atta’ and the Kharijites, and of the Kharijites and their rebellions during Umayyad and Abbasid times. Unfortunately, he was unable to complete his studies. Perhaps this was due to the limited availability of materials for his research. In the 1980s – 90s, the French scholar, Pierre Cuperly, published remarkable works focusing on the methodology for studying the early Ibāḍī theological epistles. Cuperly’s main work provides an introduction to Ibāḍī Theology. He selected three creeds from early Ibāḍī epistles and tried to explore the development of Ibāḍī beliefs up to the 6th/12th century. Overall, German Scholars Wilferd Madelung and Josef van Ess reached the pinnacle of achievement in expounding Ibāḍī Theology, as they are the primary modern contributors to fostering the understanding of Islamic theology. They re-examined classical Islamic theological history and induced other scholars to explore how early Islamic theology emerged. Their numerous publications have opened a new dimension in the study