Among the various authors, early and modern, who have investigated the activities of the four sects under discussion, it is generally agreed that Bayān ibn Sam‵ān and his followers, the Bayāniyya, were the first of the extremist groups to surface in Iraq. For that reason, we propose looking initially at this group with a view to determining its nature and historical impact. The emphasis will be upon the ideas and tactics that seem to have been peculiar to this group.

Bayān b. Sam‵ān was of Arab extraction. Some sources refer to him as Bayān al-Tamīmī, but there are strong indications that he did not in fact belong to this tribe. Rather it seems that he was a member of the Banū Nahd, one of the South Arabian tribes that had played an important role in the rebellion of al-Mukhtār in Kufa. Since he was a native of Kufa, where he is supposed to have earned his livelihood as a vendor of straw, one may conjecture that he was by no means a member of the religious or political establishment of his city.

According to some accounts, Bayān was at one time a follower of an individual named Hamza b. ‵Umāra, an adherent of the group known variously as the Karbiyya or Karibiyya. Hamza is said to have called Muhammad b. al-Hanafiyya (the individual to whom al-Mukhtār referred as Imām and Mahdī) God and himself a prophet.