The merciless civil war among the Abbasids…

The merciless civil war among the Abbasids entails severe persecution for non-Muslims.

Al-Muqanna‘ was instrumental to the formation of the Khurramiyya, a communistic sect that claims Abū Muslim to be the Mahdi and denies his death.

Under the leadership of Bābak, the Khurammites proclaim the breakup and redistribution of all the great estates and the end to despotic foreign rule.

Taking advantage of the turmoil created by the Abbasid civil war, in 816 they began making attacks on Muslim forces in Iran and Iraq.