Manichaeans and all kinds of freethinkers.

4. _Reign of Hadi_.--On the death of Mahdi, Harun, following the advice
of Yahya. b. Khalid, sent the insignia of the Caliphate, with letters of
condolence and congratulation, to Musa in Jorjan, and brought the army
which had accompanied Mahdi peacefully back from Media to Bagdad. Musa
returned in all haste to the capital, and assumed the title of _al-Hadi_
("he who directs"). The accession of a new caliph doubtless appeared to
the partisans of the house of Ali a favourable opportunity for a rising.
Hosain b. Ali b. Hasan III. raised an insurrection at Medina with the
support of numerous adherents, and proclaimed himself caliph. Thence he
went to Mecca, where on the promise of freedom many slaves flocked to
him, and many pilgrims also acknowledged him. Suleiman b. Mansur, the
caliph's representative in the pilgrimage of that year, was entrusted
with the command against him. Hosain was attacked at Fakh, 3 m. from
Mecca, and perished in the combat with many other Alids. His maternal
uncle, Idris b. Abdallah, a brother of Mahommed and Ibrahim, the rivals
of Mansur, succeeded in escaping, and fled to Egypt, whence by the help
of the postmaster, himself a secret partisan of the Shi'ites, he passed
into West Africa, where at a later period his son founded the Idrisite
dynasty in Fez (see MOROCCO).

Hadi, who had never been able to forget that he had narrowly escaped
being supplanted by his brother, formed a plan for excluding him from
the Caliphate and transmitting the succession to his own son Ja'far. To
this he obtained the assent of his ministers and the principal chiefs of
his army, with the exception of Yahya b. Khalid, Harun's former tutor,
who showed such firmness and boldness that Hadi cast him into prison and
resolved on his death. Some historians say that he had already given
orders for his execution, when he himself was killed (September 14th,
786) by his mother Khaizoran, who had systematically and successfully
intrigued against him with the object of gaining the real power for
herself. Hadi, indignant at the fact that she was generally regarded as
the real source of authority, had attempted to poison her, and
Khaizoran, hoping to find a more submissive instrument of her will in
her second and favourite son, caused Hadi to be smothered with cushions
by two young slaves whom she had presented to him. She herself died
three years later.

5. _Reign of Harun al-Rashid_.--W