Ibadi School

The Ibadi school traces its lineage to the aftermath of one of early Islam's sharpest political ruptures. When the fourth caliph Ali agreed to arbitration with his rival Muawiya after the Battle of Siffin in 657, a group of his own supporters broke away, holding that submitting a matter of leadership to human arbitration when God's judgment had already been given by force of arms was itself a betrayal. This group became known as the Kharijites, and its more militant wing went on to a reputation for taking radical positions, including declaring other Muslims unbelievers over serious sin and, in some factions, sanctioning violence against them.

Ibadism descends from the movement's moderate, quietist wing, which rejected that militancy while keeping the underlying conviction that leadership belonged to whoever was most qualified by piety and learning, from any tribe or lineage, rather than by descent from the Prophet's family or by the Umayyad and Abbasid dynastic claims that came to dominate elsewhere. In Basra, the scholar Jabir ibn Zayd al-Azdi is credited by Ibadi tradition with giving this position a settled legal and theological system distinct from both the Sunni majority, which accepted the Umayyad and later caliphates as legitimate, and from the Shia, who held that leadership belonged specifically to Ali's descendants. The result was neither Sunni nor Shia, a third position that has survived, unusually among the Kharijite movement's many branches, into the present day.

Ibadi communities spread out from Basra along trade routes into North Africa and Arabia in the centuries after the school's formation, and for a period an Ibadi dynasty, the Rustamids, governed an imamate centered on Tahert in what is now Algeria from the mid eighth century until its fall to the Fatimids in 909. When that state collapsed, Ibadi communities in the Maghreb persisted mainly as a minority presence in Algeria's Mzab valley and on the Tunisian island of Jerba, holding their distinctive legal tradition without a state of their own to enforce it.

Oman took the opposite path. Ibadism became established there early and, through a long and interrupted history of Imamate government, remained the school followed by the country's majority population into the present, giving Oman a legal-religious identity distinct from both its Sunni Gulf neighbors and Shia Iran across the strait. Modern Oman under the Al Said dynasty has not restored the historical Imamate as a political office, but Ibadi jurisprudence continues to inform the country's legal and religious institutions, and Omani Ibadi scholarship remains the tradition's most active living center, alongside smaller communities that maintain the same school in East Africa, a legacy of Omani trade and, in Zanzibar's case, of direct Omani rule during the nineteenth century.