ing
tribe, the Shaiban, possessed the lands on the Tigris in the province of
Mosul, and here, after the murder of Walid II., their chief proclaimed
himself caliph. Reinforced by many Kharijites out of the northern
provinces, he marched against Kufa. Ibn Omar and Ibn Sa'id al Harashi
tried to defend their province, but were completely defeated. Harashi
fled to Merwan, Ibn Omar to Hira, which, after a siege of two months, he
was obliged to surrender in Shawwal 127 (August A.D. 745). Mansur b.
Jomhur was the first to pass over to the Khawarij; then Ibn Omar himself
took the oath of allegiance. That a noble Koreishite, a prince of the
reigning house, should pledge himself to follow Dahhak the Shaibanite as
his Imam, was an event of which the Khawarij were very proud. Ibn Omar
was rewarded with the government of eastern Irak, Khuzistan and Fars.

Whilst Merwan besieged Homs, Dahhak returned to Mesopotamia and took
Mosul, whence he threatened Nisibis, where Abdallah, the son of Merwan,
maintained himself with difficulty. Suleiman b. Hisham also had gone
over to the Khawarij, who now numbered 120,000 men. Mesopotamia itself
was in danger, when Merwan at last was able to march against the enemy.
In a furious battle at Kafartutha (September A.D. 746) the Khawarij were
defeated; Dahhak and his successor Khaibari perished; the survivors were
obliged to retire to Mosul, where they crossed the Tigris. Merwan
followed them and encamped on the western bank. Immediately after the
battle of Kafartutha, Yazid b. Omar b. Hobaira directed his troops
towards Irak. He beat the Kharijites repeatedly and entered Kufa in May
or June 747. Ibn Omar was taken prisoner; Mansur b. Jomhur fled to Ibn
Moawiya. Ibn Hobaira was at last free to send Ibn Dobara with an army to
Mesopotamia. At his approach the Kharijites left their camp and fled to
Abdallah b. Moawiya, who was now at the height of his power. But it was
not destined to last. The two generals of Ibn Hobaira, Ibn Dobara and
Nobata b. Hanzala defeated his army; Ibn Moawiya fled to Khorasan, where
he met his death; the chief of the Kharijites, Shaiban Yashkori went to
eastern Arabia; Suleiman b. Hisham and Mansur b. Johmur escaped to
India. Thus, at last, the western and south-eastern parts of the empire
lay at the feet of Merwan. But in the north-east, in Khorasan, meanwhile
a storm had arisen, against which his resources and his wisdom were
alike of no avail.

When the news of the murder of