The Ibadiyya is one of the main branches of Islam. The main difference between the Ibadis and the rest of the Muslim community is primarily rooted in political theory. The Ibadis are relatively few in number in comparison to the Sunnis and the Shi'is, and for many centuries they have lived largely in isolated areas, principally Oman and Zanzibar, Tripolitania in Libya, the island of Jerba in Tunisia, and the Mzab area of Algeria. However, since the accession of Qaboos Ibn Said to the sultanate of Oman in 1970, there has been a sustained program for the publication of major Ibadi works, so that it is at last becoming possible to view the Ibadis through their own tradition. Unfortunately, very little has so far trickled through into English.
The origins of the Ibadis go as far back as twenty years after the Prophet Muhammad’s death. What split the early Islamic community in the first instance were views about the actions of the third caliph, Uthman, and the fourth caliph, Ali. There was much opposition both to Uthman, who was murdered by some of his opponents, and to Ali.
When Ali was killed in 661 CE, the Umayyads came to power, and for a time some stability was imposed. By the time of the Second Civil War (688–692 CE), the principal quietist group, living mainly in Basra, had become known as the Ibadiyya. This name derives from Abdallah Ibn Ibad, who appears to have been the political mentor of the group, though its spiritual leader was Jabir Ibn Zayd, a man widely recognized for his learning and piety, who became the first imam of the group.
While Jabir was alive, the Ibadiyya were more or less tolerated by the central authorities. The community devised rules, which still hold, to enable them to survive among a non-Ibadi Muslim majority (qawm). Thus it is permitted to marry non-Ibadis and to enjoy mutual inheritance with them. Concealment (kitman) is also permitted, though not to the point of serving non-Ibadi rulers.
After the death of Jabir Ibn Zayd in 711 CE, the Ibadis found it more and more difficult to live in Basra, and their next two imams encouraged them to migrate to places where they could follow their own teachings without harassment. Most moved to the remote parts of the Arab world—Oman, Hadramawt, Yemen, and North Africa—although some also went to Khurasan. It was only in Oman and Waad Mzab valley that they survived in numbers, with a religious, legal, and political tradition going back unbroken to their earliest days in Basra.In legal matters the Ibadis put more weight on the Qur'an and less on the Hadith than other branches of Islam. Thus, they do not impose the (non-Qur'anic) punishment of stoning for adultery, for example. The nature of their community has also led preserving Ijtihad. Unlike the Sunnis but like the Shi'is, they have never closed the gates of Ijtihad.