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.
