After the death of Husayn...

After the death of Husayn, however, the majority of Shī'ites placed their trust in 'Alī ibn al-Husayn Zayn al-'Ābidīn,[^6] while a minority, known as al-Kaysaniyyah, believed that the right to succession belonged to Muhammad ibn al-Hanafiyyah. He was the third son of 'Alī, but not through Fātimah. As a result, he cannot be considered a descendant of the Prophet.[^7] Despite this fact, Muhammad ibn Hanafiyyah was proclaimed by his partisans as the Fourth Imām and the promised Mahdī.

During the time he sought refuge in the mountains of Rawdah, which form a cordillera in Madīnah, Mukhtār al-Thaqāfī served as his “representative.”[^8] It was believed that Muhammad ibn Hanafiyyah would come down one day and appear as the rightly-guided and long-awaited Messiah. In accordance with Shī'ite thought, the Mahdī is a man motivated by God who is also a military chief and a warrior.

Even if the followers of Mukhtār al-Thaqāfī gave an extremist character to the eschatological idea of the Hidden Imām, the Islāmic figure of the Messiah as restorer of revealed religion is not an invention of Mukhtār or a Christian influence. The Mahdī is a spiritual synthesis of all revealed forms and not a mere uniform syncretism.

It is a concept that is expressed in all its dimensions and depth in many ahādīth of the Prophet as well as many traditions of the Imāms.[^9] In synthesis, we can say that after the death of Imām Zayn al-'Ābidīn, the majority of Shī'ites accepted Muhammad al-Bāqir as the Fifth Imām, despite the fact that a minority followed his brother Zayd al-Shahīd, who were known from that moment on as Zaydīs.[^10] Imām Muhammad al-Bāqir was succeeded by his son Ja'far al-Sādiq the Sixth Imām and, after his death, his son Mūsā al-Kāzim was recognized as the Seventh Imām.

Nevertheless, an opposition group insisted that the successor of the Sixth Imām was his elder son Ismā'īl who had died when his father was still alive.[^11] This group split from the Shī'ite majority and became known as the Ismā'īlis. Others, instead, preferred 'Abdullāh al-Aftah and some even chose Muhammad, both sons of the Sixth Imām. Still, there were even those who considered Ja'far al-Sādiq as the Last Imām and were convinced that none would succeed him.

Likewise, after the martyrdom of Imām Mūsā al-Kāzim, the majority followed his son 'Alī al-Ridā as the Eighth Imām.