Editing Fatimid dynasty (section)

===Background: early Shi'ism===
Since the death of [[Caliph]] [[Ali]] ({{Reign|656|661}}) in 661, which led to the establishment of the [[Umayyad Caliphate]], a part of the [[Muslim community]] rejected the Umayyads as usurpers and called for the establishment of a regime led by a member of the {{Transliteration|ar|[[ahl al-bayt]]}}, the family of Muhammad. The [[Abbasid dynasty|Abbasids]], who claimed descent from Muhammad's paternal uncle [[Abbas ibn Abd al-Muttalib]] and thus claimed membership of the wider family, profited from this during their [[Abbasid Revolution|rise to power]] against the Umayyads; but their claim was rejected by the [[Shia Islam|Shia]], who insisted on the exclusive right of the descendants of [[Hasan ibn Ali|Hasan]] ({{Died in|670}}) and [[Husayn ibn Ali|Husayn]] ({{Died in|680}}), Ali's sons by Muhammad's daughter [[Fatimah|Fatima]].{{sfn|Brett|2017|p=18}} A line of [[Imamate in Shia doctrine|imams]] emerged from the offspring of Husayn, who did not openly lay claim to the caliphate, but were considered by their followers as the true representatives of God on earth.{{sfn|Brett|2017|p=18}} This doctrine was founded on the designation ({{Transliteration|ar|[[nass (Islam)|nass]]}}) of Ali by Muhammad at [[Ghadir Khumm]], and later pro-Fatimid scholars held that an unbroken chain of designated imams would follow until the end of the world; indeed, these scholars argued that the imams' existence was an inevitable necessity.{{sfn|Brett|2001|p=31}}

The sixth of these imams, [[Ja'far al-Sadiq]], appointed ({{transliteration|ar|[[nass (Islam)|nass]]}}) his son [[Isma'il al-Mubarak]] as his successor, but Isma'il died before his father, and when al-Sadiq himself died in 765, the succession was left open. One faction of al-Sadiq's followers held that he had designated another son, [[Musa al-Kazim]], as his heir. Others followed other sons, [[Muhammad ibn Ja'far al-Sadiq|Muhammad al-Dibaj]] and [[Abdallah al-Aftah|Abd Allah al-Aftah]]—as the latter died soon after, his followers went over to Musa's camp—or even refused to believe that al-Sadiq had died, and expected his return as a [[messiah]].{{sfn|Daftary|2007|pp=88–89}} Musa's adherents, who constituted the majority of al-Sadiq's followers, followed his line down to a twelfth imam who supposedly [[Occultation (Islam)|vanished]] in 874. Adherents of this line are known as the [[Twelver Shi'ism|Twelvers]].{{sfn|Brett|2017|p=18}}{{sfn|Daftary|2007|p=89}} Another branch believed that Ja'far al-Sadiq was followed by a seventh imam, who also had gone into hiding; hence this party is known as the Seveners. The exact identity of that seventh imam was disputed, but by the late ninth century had commonly been identified with [[Muhammad ibn Isma'il|Muhammad]], son of Isma'il and grandson of al-Sadiq. From Muhammad's father, Isma'il, the sect receives its name of 'Isma'ili'.{{sfn|Brett|2017|p=18}}{{sfn|Halm|1991|pp=27–28}}{{sfn|Daftary|2007|pp=89–90}} Neither Isma'il's nor Muhammad's lives are well known, and after Muhammad's reported death during the reign of [[Harun al-Rashid]] ({{reign|786|809}}), the history of the early Isma'ili movement becomes obscure.{{sfn|Daftary|2007|pp=90–96}}