We need not linger over the family of al-Hasan and his descendants. They were involved in `Alid risings at Madina, and after the suppression of one of these in 169, long after the fall of the `Umayyads, Idris the great-grandson of al-Hasan escaped to the far West and established a “moderate” Shi`ite Dynasty in what is now Morocco, so that the subsequent history of that house concerns the history of the West.

Most of the Shi`ites regard the third Imam, al-Husayn as being succeeded by his son `Ali Zayn. Al-Husayn, like al-Hasan, was not only the son of `Ali, but also of the Prophet’s daughter, Fatima. In al-Husayn’s case moreover there was another heritage which ultimately proved more important than descent from either `Ali or Fatima: he was generally supposed to have married the daughter of the last of the Persian kings, the “mother of the Imams,” and this traditional marriage with the Persian princess,—its historical evidence is very dubious—has been regarded by the Persian Shi`ites as the most important factor in the Imamate, although this, of course, has nothing whatever to do with the religion of Islam. That so great weight could be attached to such a consideration serves to show how really foreign and non-Muslim a thing the Shi`a is. `Ali Zayn had two sons, Zayd and Muhammad al-Bakir. Of these Zayd was a pupil of Wasil b. `Ata and associated with the Mu`tazilite movement: he is generally regarded as a rationalist. Indeed, as we shall now see frequently, the heretical Shi`ite party was very generally mixed up with free thought and frequently shows adherence to Greek philosophy: it seems as though its inspiring spirit was hostility towards orthodox Islam, and a readiness to ally itself with anything which tended to criticize unfavourably the orthodox doctrines. Zayd had a body of followers who established themselves in North Persia where they held their own for some time, and a branch of their party still exists in South Arabia, still suspected of rationalist proclivities. Most of the Shi`ites, however, recognised Muhammad al-Bakir as the fifth Imam, and Ja`far as-Sadiq as the sixth. This latter also was a devoted follower of the “new learning,” that is to say, of Hellenistic philosophy, and is generally regarded as the founder, or at least the chief exponent, of what are known as batinite views, that is to say the allegorical interpretation of the Qur´an, so that revelation is made to mean, not the literal statement, but an inner meaning, and this inner meaning generally shows a strong influence of Hellenistic philosophy. It is only the divinely directed Imam who can expound the true meaning of the Qur´an which remains a sealed book to the uninitiated. Ja`far was, it would appear, the first of the `Alids who openly asserted that he was a divine incarnation as well as an inspired teacher: his predecessors had done no more than acquiesce in such claims when made by their followers, and very often had repudiated them.

Abu Hashim, the son of Muhammad b. al-Hanafiya, died in 98 A.H. poisoned, it was generally believed, by the Khalif Sulayman, and bequeathed his rights to Muhammad b. `Ali b. `Abdullah, a descendant of the house of Hashim, to which the Prophet and `Ali had belonged, the rival clan of the Quraysh tribe opposed to the clan of the `Umayyads. Abu Hashim assumed that the Imamate was his to be passed on to whom he saw fit, a view of the Imamate which was not accepted by the stricter Shi`ites who were legitimists, but the partisans of Abu Hashim do not seem to have been extremists in spite of their Kaysanite origin. In 99 the Khalifate passed to Umar II. the one `Umayyad who showed `Alid sympathies, putting an end to the public cursing of `Ali which had formed part of the public ritual in the mosques of Damascus since the days of Mu`awiya and who represented a type of personal piety to which the `Umayyad Khalifs had hitherto been strangers. His brief reign of less than three years did not, however, remove the evils of tyranny and misgovernment, and he was followed by other rulers more in conformity with the old bad type.

About the time of Umar’s death a deputation of Shi`ites waited upon Muhammad b. `Ali the Hashimite, a man of noted piety and the one who had now become, as legatee of Abu Hashim the son of Muhammad b. al-Hanafiya, the recognised head of an important wing of the Shi`ites, and swore to support him in an endeavour to obtain the Khalifate “that God may quicken justice and destroy oppression” (Dinwari: Akhbaru t-Tiwal. ed. Guirgass, Leiden. p. 334): and Muhammad had answered that “this is the season of what we hope and desire, because one hundred years of the calendar are completed.” (id.)

The supporters of the family of Muhammad b. al-Hanafiya, who had now transferred their allegiance to Muhammad b. `Ali, were extremely important, not so much by reason of their numbers as by their excellent organisation. They had developed a regular system of missionaries (da`i, plur. du`at) who travelled under the guise of merchants and confined their teaching to private instructions and informal intercourse, a method which has become the standard type of Muslim missionary propaganda. By Abu Hashim’s death and legacy Muhammad b. `Ali found this very fully organised missionary work at his service, and its emissaries were fully confident that his acceptance of the overtures of the Shi`ite deputation meant that he stood as the champion of Shi`ite claims. The stricter Shi`ites who followed the house of al-Husayn did not admit the claims of Muhammad b. al-Hanafiya or his descendants, but they supported Muhammad b. `Ali’s efforts under the impression that he was a Shi`ite champion.

The propaganda in favour of Muhammad b. `Ali is sometimes referred to as `Abbasid because he was descended from al-`Abbas, one of the three sons of `Abdu l-Muttalib, and so brother of Abu Talib the father of the Imam `Ali and of `Abdullah who was grandfather of the Prophet Muhammad. At the time, however, the missionaries claimed rather to be the supporters of the Hashimites, a term which was ambiguous, perhaps intentionally so. It was afterwards explained as referring to the house of Hashim which was the rival clan of the Quraysh opposed to the `Umayyads and that to which the Prophet, and `Ali, and al-`Abbas belonged: but in the minds of many of the Shi`ites it was taken to mean the followers of Abu Hashim, the grandson of Al-Hanafiya.

Muhammad b. `Ali died in 126 A.H. leaving three sons, Ibrahim, Abu l-Abbas, and Abu Ja`far, the first of these being recognised as his successor. About the same time Abu Muslim, who became governor of Khurasan in 129 comes into prominence. It is dubious whether he was an Arab or a native of `Iraq (cf. Masudi. vi. 59), indeed, the claim was made that he was a descendant of Gandarz, one of the ancient kings of Persia (id.) Now Khurasan was the area most disaffected towards the `Umayyads, and there the Hashimite missionaries had been most active and successful. Abu Muslim threw himself into this work heartily and began gathering together an armed body of men who before long numbered 200,000. Information and warning was sent to the Khalif Marwan II. but was ignored: indeed the court at Damascus took no notice until 130. Abu Muslim at length openly raised the black standard as the signal of revolt against the `Umayyads whose official colour was white. Then all the Khalif did was to seize Muhammad b. `Ali’s son Ibrahim and put him to death. The other two sons escaped and fled to Kufa where they were sheltered and concealed by some Shi`ites, the second son Abu l-`Abbas, known to history as as-Saffah “the butcher” being recognised as the Hashimite leader.

Abu Muslim’s success was rapid and complete, and in 132 the `Umayyad dynasty was overthrown and partly exterminated, and so “the butcher” became the first of the `Abbasid Khalifs, so called as being of the family of al-`Abbas the son of `Abdu l-Muttalib.

As soon as the Khalif Abu l-`Abbas was seated on the throne his chief aim was to secure the establishment of his dynasty by getting rid of all possible rivals, and it was the vigour he showed in doing this which earned for him the title of “the Butcher.” First of all he hunted down and slew all the representatives he could find of the `Umayyad family. One of these escaped, `Abdu r-Rahman, and went to Africa where he endeavoured to form a body of supporters without success, and then crossed over to Spain where in 138 he established himself at Cordova, and there he and his descendants ruled until 422 A.H. These Spanish `Umayyads claimed to be legitimist rulers, but never assumed the divine claims of the `Alid section.

Abu Muslim, who had done most to establish the `Umayyad dynasty, next provoked the Khalif’s jealousy, probably with good cause for he was indignant to find that “the Butcher” was no sooner on the throne than he entirely discarded the Shi`ites who had helped to place him there, and so within the first year of the `Abbasid rule Abu Muslim was put to death.