of which was
attributed to Khalid. Though it soon appeared that the imputation was
false, Khalid, on his return, was furious, and uttered very offensive
words against the caliph. Hisham, however, would not again punish his
old servant; on the contrary, he seems to have regarded his indignation
as a proof of innocence.

The successor of Khalid in Irak had not long been in office when Zaid b.
Ali, grandson of Hosain b. Ali, who had come to Kufa for a lawsuit, was
persuaded by the chiefs of the Shi'a to organize a revolt. He succeeded
in so far that 15,000 Kufians swore to fight with him for the
maintenance of the commandments of the Book of God and the _Sunna_
(orthodox tradition) of his Prophet, the discomfiture of the tyrants,
the redress of injury, and last, not least, the vindication of the
family of the Prophet as the rightful caliphs. The revolt broke out on
the 6th of January 740. Unfortunately for Zaid he had to do with the
same Kufians whose fickleness had already been fatal to his family. He
was deserted by his troops and slain. His body was crucified in Kufa,
his head sent to Damascus and thence to Medina. His son Yahya, still a
youth, fled to Balkh in Khorasan, but was discovered at last and hunted
down, till he fell sword in hand under Walid II. Abu Moslim, the founder
of the Abbasid dynasty, proclaimed himself his avenger, and on that
occasion adopted the black garments, which remained the distinctive
colour of the dynasty.

In Khorasan also there were very serious disturbances. The Sogdians,
though subdued by Sa'id al Harashi, were not appeased, but implored the
assistance of the Turks, who had long been contending earnestly against
the Arabs for the dominion of Transoxiana. They found besides a most
valuable ally in Harith b. Soraij, a distinguished captain of the Arabic
tribe of Tamim, who, with many pious Moslems, was scandalized by the
government's perfidy in regard to the new converts. Harith put himself
at the head of all the malcontents, and raised the black flag, in
compliance with a Sibylline prophecy, holding that the man with the
black flag (the Prophet's flag) would put an end to the tyranny, and be
the precursor of the Mahdi.[22] The government troops suffered more than
one defeat, but in the last month of the year 118 (A.D. 736) the
governor Asad al-Qasri, the brother of Khalid, after having defeated
Harith, gained a brilliant victory over the Turks, which finally caused
them to retreat. Asa