The Ibadi movement, Ibadism or Ibiyya, also known as the Ibadis (Arabic: , al-Ibiyyah), is a school of Islam dominant in Oman. It is also found in parts of Algeria, Tunisia, Libya and East Africa. The movement is said to have been founded around the year 650 CE or about 20 years after the death of the Islamic prophet Muhammad, predating both the Sunni and Shia denominations. Modern historians trace back the origins of the denomination to a moderate current of the Khawarij movement;:3 contemporary Ibs strongly object to being classified as Kharijites, although they recognize that their movement originated with the Kharijite secession of 657 CE.:3
The school derives its name from ?Abdu l-L?h ibn Ib of the Banu Tamim. Ibn Ibad was responsible for breaking off from the wider Kharijite movement roughly around the time that Abd al-Malik ibn Marwan, the fifth Umayyad ruler, took power.:11 However, the true founder was J?bir ibn Zayd of Nizwa, Oman.:12 Initially, Ibadi theology developed in Basra, Iraq. The Ibadis opposed the rule of the third caliph in Islam, Uthman ibn Affan, but unlike the more extreme Kharijites the Ibadis rejected the murder of Uthman as well as the Kharijite belief that all Muslims holding differing viewpoints were infidels. The Ibadis were among the more moderate groups opposed to the fourth caliph, Ali, and wanted to return Islam to its form prior to the conflict between Ali and Muawiyah I. They called themselves Muhakkima, Muhakkima (Arabic: ) and al-Haruriyya (Arabic: ) refers to the Muslims who rejected arbitration between Ali ibn Abi Talib and Mu'awiya at the Battle of Siffin in 657 CE. The name Mu?akkima derives from their slogan la hukma illa li-llah, meaning "judgment (hukm) belongs to God alone". The name al-Haruriyya refers to their withdrawal from Ali's army to the village of Harura' near Kufa. This episode marked the start of the Kharijite movement, and the term mu?akkima is often also applied by extension to later Kharijites.
Due to their opposition to the Umayyad Caliphate, the Ibadis attempted an armed insurrection starting in the Hijaz region in the 740s. Caliph Marwan II led a 4,000 strong army and routed the Ibadis first in Mecca, then in Sana'a in Yemen, and finally surrounded them in Shibam in western Hadhramaut. Problems back in their heartland of Syria forced the Umayyads to sign a peace accord with the Ibadis, and the sect was allowed to retain a community in Shibam for the next four centuries while still paying taxes to Ibadi authorities in Oman. For a period after Marwan II's death, Jabir ibn Zayd maintained a friendship with Umayyad general Al-Hajjaj ibn Yusuf, who supported the Ibadis as a counterbalance to more extreme Kharijites. Ibn Zayd ordered the assassination of one of Al-Hajjaj's spies, however, and in reaction many Ibadis were imprisoned or exiled to Oman.:12[dubious ]
It was during the 8th century that the Ibadis established an imamate in the inner region of Oman. The position was an elected one, as opposed to Sunni and Shi'a dynasties where rule was inherited. These imams exerted political, spiritual and military functions.
By the year 900, Ibadism had spread to Sind, Khorosan, Hadhramaut, Dhofar, Oman proper, Muscat, the Nafusa Mountains, and Qeshm; by 1200, the sect was present in Al-Andalus, Sicily, M'zab (the Algerian Sahara), and the western part of the Sahel region as well. The last Ibadis of Shibam were expelled by the Sulayhid dynasty in the 12th century. In the 14th century, historian Ibn Khaldun made reference to vestiges of Ibadi influence in Hadhramaut, though the sect no longer exists in the region today.
Despite predating all Sunni and Shia schools by several decades, the Ibadis and their beliefs remain largely a mystery to outsiders, both non-Muslims and even other Muslims.:3 Ibadis have claimed, with justification, that while they read the works of both Sunnis and Shias, even the learned scholars of those two sects never read Ibadi works and often repeat myths and false information when they address the topic of Ibadism without performing proper research.:4 The isolated nature of Oman granted the Ibadi denomination, secretive by nature, the perfect environment to develop in isolation from the Islamic mainstream. Ibadis were cut off even from the Kharijite sect because of Ibn Iba?'s criticism of their excesses and his rejection of their more extreme beliefs. The spread of Ibadism in Oman essentially represents the triumph of theology over tribal feudalism and conflict.
Ibadis have been referred to as tolerant Puritans or as political quietists because of their preference to solve differences through dignity and reason rather than with confrontation, as well as their tolerance for practising Christians, Hindus, Sikhs and Jews sharing their communities. Muscat, Oman presently has churches, temples, and gurudwaras.
Ibadism's movement from Hijaz to Iraq and then further out made Ibadi historian al-Salimi once write that Ibadism is a bird whose egg was laid in Medina, hatched in Basra and flew to Oman. Alongside Hanafi, Zaydi and Ismailism, Ibadism is among the oldest extant Islamic schools of thought, dating back to the eight century.
Ibadis state, with reason, that their school predates that of mainstream Islamic schools, and Ibadism is thus considered to be an early and highly orthodox interpretation of Islam.
Ibs have several doctrinal differences with other denominations of Islam, chief among them:
Ibadis agree with Sunnis, regarding Abu Bakr and Umar ibn al-Khattab as rightly-guided caliphs.:7 They regard the first half of Uthman ibn Affan's rule as righteous and the second half as corrupt and affected by both nepotism and heresy.:7 They approve of the first part of Ali's caliphate and (like Sh?'a) disapprove of Aisha's rebellion and Muawiyah I's revolt. However, they regard Ali's acceptance of arbitration at the Battle of ?iff?n as rendering him unfit for leadership, and condemn him for killing the Khawarij of an-Nahr in the Battle of Nahrawan. Modern Ibadi theologians defend the early Kharijite opposition to Uthman, Ali and Muawiyah.:10
Moroccan explorer Ibn Battuta observed Ibadis praying Jumu'ah in Oman and said they prayed in the same manner as Zuhr prayer. He noticed that they invoked God's mercy on Abu Bakr and Umar but not Uthman and Ali.
In their belief, the next legitimate caliph was Abdullah ibn Wahb al-Rasibi, the leader of the Kharijites who turned against Ali for his acceptance of arbitration with Muawiyah.:10 All Caliphs from Mu'?w?yah onward are considered tyrants except Umar ibn Abdul Aziz, on whom opinions differ. Numerous Ib leaders are recognized as true imams, including Abdullah ibn Yahya al-Kindi of South Arabia and the imams of the Rustamid dynasty in North Africa. Traditionally, conservative Omani Ibadism rejected monarchy and hereditary rule, and Ibadhi leaders were elected.
Despite bitter religious disputes elsewhere, the Ibadis are realists and believe that reason and political expediency must temper the ideal Islamic state.
Ibadis accept as authentic far fewer hadith than do Sunnis. Several Ibadi founding figures were noted for their hadith research, and Jabir ibn Zayd is accepted as a reliable narrator even by Sunni scholars as well as by Ibadis. After the death of Ibn Ibad, Ibn Zayd led the Ibadis and withdrew to Oman, where his hadith, along with those of other early Ibadis formed the corpus of their interpretation of Islamic law.
The development of Ibadi theology happened thanks to the works of scholars and imams of the community, whose histories, lives, and personalities are part of the Islamic history. Ib theology can be understood on the basis of their works Ibn Ib, J?bir bin Zayd, Ab? 'Ubaida, Rab?' b. ?ab?b and Ab? Sufy?n among others. Basra is the foundation of the Ib community. Various Ib communities that were established in southern Arabia, with bases in Oman, North Africa, and East Africa mainly.
The fiqh or jurisprudence of Ibadis is relatively simple. Absolute authority is given to the Qur'an and hadith; new innovations accepted on the basis of qiyas, or analogical reasoning, were rejected as bid'ah by the Ibadis. That differs from the majority of Sunnis (except minority Zahiri and early Hanbali schools of Sunnism) but agrees with Shias.
The Wahbi is considered to be the most mainstream of the schools of thought within Ibadism.  The main reason why the Wahbi strain has come to dominate within Ibadism is that most textual references that have been preserved can be attributed to Wahbi affiliated scholars.
The dating of early writings such as kutub al-rudud and siras (letters) written by Ibadis has led some analysts such as Salim al-Harithi to claim Ibadism as the oldest sect within Islam. However others suggest Ibadism only took on characteristics of a sect and a full-fledged madhab during the demise of the Rustamid Imamate.
The term Wahbi is chiefly derived as an eponymous intimation to the teachings of Abdullah bin Wahb al-Rasibi. Although the term Wahbi was initially considered superfluous as Ibadism was largely homogenous, its usage increased upon the advent of the Nukkari secession in order to differentiate the Wahbis from the off-shoot Ibadis. The most common epithet Wahbi Ibadi clerics enjoined their adherents to apply to themselves is the term ahl al istiqama meaning those on the straight path. They rejected the usage of ahl al -sunnah as early usage assigned the term sunnah as the practise of Muawiyah cursing Ali ibn Abi Talib from the pulpits, although during the Ummayad era, this meaning changed.
Ibadis make up a majority (roughly 75%) of the population in Oman. There are roughly 2.72 million Ibadis worldwide, of which 250,000 live outside Oman. As a result, Oman is the only country in the Muslim world with an Ibadi-majority population.
Historically, the early medieval Rustamid dynasty in Algeria was Ibadi, and refugees from its capital, Tiaret, founded the North African Ibadi communities, which still exist in M'zab. The Mozabites, a Berber ethnic group in M'zab, are Ibadis. Ibadism also exists elsewhere in Africa, particularly in Zanzibar in Tanzania, the Nafusa Mountains in Libya, Djerba Island in Tunisia, and among the Dishiishe clan of Somalis.