Such divisions exist in all traditions and religions, and more particularly in the four "revealed" religions of Judaism, Christianity, Zoroastrianism, and Islam. Shi’ism did not undergo any divisions during the imamate of the first three Imams: Ali, Hasan, and Husayn. But after the martyrdom of Husayn, the majority of the Shi’ites accepted the imamate of Ali ibn Husayn al-Sajjad, while a minority known as the Kisaniyah believed that the third son of Ali, Muhammad ibn Hanafiyah, was the fourth Imam as well as the promised Mahdi, and that he had gone into occultation in the Radwa mountains and one day would reappear. After the death of Imam al-Sajjad the majority of the Shi’ites accepted as Imam his son, Muhammad al-Baqir, while a minority followed Zayd al-Shahid, another son of Imam al-Sajjad, and became known as Zaydis.
Following Imam Muhammad al-Baqir, the Shi’ites accepted his son Ja’far al-Sadiq as Imam and after the death of Imam Ja’far the majority followed his son Imam Musa al-Kazim as the seventh Imam. However, one group followed the older son of the sixth Imam, Isma’il, who had died while his father was still alive, and when this latter group separated from the majority of Shi’ites it became known as Isma’ilis. Others accepted as Imam either ’Abdollah al-Aftah or Muhammad, both sons of the sixth Imam. Finally, another party stopped with the sixth Imam himself and considered him as the last Imam. In the same way, after the martyrdom of Imam Musa al-Kazim the majority followed his son, Ali al-Rida, as the eight Imam. However, some stopped with the seventh Imam and became known as the Waqifiyah.
From the eighth Imam to the twelfth, whom the majority of the Shi’ites believe to be the promised Mahdi, no division of any importance took place within Shi’ism. Even if certain events occurred in the form of division, they lasted but a few days and dissolved by themselves. For example, Ja’far, the son of the tenth Imam, claimed to be Imam after the death of his brother, the eleventh Imam. A group of people followed him but scattered in a few days and Ja’far himself did not follow his claim any further. Further more, there are differences between Shi’ites in theological and juridical matters which must not be considered as division in religious schools. Also the Babi and Baha’i sects, which like the Batinis (the Qaramitah) differ in both the principles (usul) and branches (furu’) of Islam from the Muslims, should in any sense be considered as branches of Shi’ism.
The sects which separated from the majority of Shi’ites all dissolved within a short period, except two: the Zaydi and the Isma’ili which continue to exist until now. To this day communities of these branches are active in various parts of the world such as the Yemen, India, and Syria. Therefore, we shall limit our discussion to these two branches along with the majority of Shi’ites who are Twelvers.
Shia Islam and the Caliphate of Imam Ali
