After the death of Husayn there were three different lines of ʿAlids which competed for the allegiance of the legitimist faction, those descended from (i.) Hasan, and (ii.) Husayn, the two sons of ʿAli by his wife Fatima, the daughter of the Prophet, and both therefore representing the next of kin to the Prophet who left no son, and (iii.) the house of Muhammad, the son of ʿAli, by another wife known as the Hanifite. Of these three we may disregard the descendants of (i.) Hasan, who ultimately migrated to Maghrab (Morocco), and became the progenitors of the Idrisid dynasty and of the Sharifs of Morocco: they formed a very moderate branch of the Shiʿite faction, adopted many practices of the orthodox or Sunni party, and had no part in the peculiarly Persian developments of the Asiatic Shiʿites. The first ʿAlid faction to become prominent was (iii.) the partisans of Muhammad, the son of the Hanifite, who were formed into a society by Kaysan, a freedman of ʿAli, for the purpose of avenging Hasan and Husayn. They recognised a succession of four Imams or valid commanders, ʿAli, Hasan, Husayn, and Muhammad, the son of the Hanifite, and maintained that, at Husayn’s death, Muhammad became _de jure_ the Khalif and the divinely appointed head of the Church of Islam. Muhammad himself entirely disowned these partisans, but that was a detail to which they paid no attention. At Muhammad’s death in A.H. 81 this party, “the Kaysanites” as they were called, recognised his son Abu Hashim as the fifth Imam until A.H. 98, when he died childless after bequeathing his claims to Muhammad b. ʿAli b. ʿAbdullah (d. A.H. 126), who was not of the house of ʿAli at all, and who became the founder of the ʿAbbasid dynasty which obtained the Khalifate in A.H. 132. It was under Abu Hashim that the party, now changed in name from Kaysanites to Hashimites, became an admirably organised conspiracy which contributed more than anything else to the overthrow of the ʿUmayyad Khalifs. Throughout the Muslim dominions there was deep and ever-increasing dissatisfaction with the ʿUmayyads, who represented an arrogant _parvenu_ Arab aristocracy, ruling over races who enjoyed an older and richer culture, and were by no means effete. The Hashimites seized hold of this discontent and sent out their missionaries (_daʿi_, plur. _duʿat_) in all directions disguised as merchants and pilgrims who relied upon private conversations and informal intercourse rather than public preaching, and thus began that unostentatious but effective propaganda, which has ever since been the chief missionary method of Islam. Hashimite teaching centered in the doctrines of _tawakkuf_ or the theory of a divinely appointed Imam, who alone was the rightful Commander of the faithful and their authoritative teacher, of _hulul_ or the incarnation of the Divine Spirit in the Imam, and of _tenasukhu l-Arwah_ or the transmigration of that Spirit from each Imam to his valid successor, doctrines alien to Islam proper.