the fall of that dynasty in the East had already prepared
the way for the independence of a province so distant from the centre of
the empire. Every petty amir then tried to seize sovereign power for
himself, and the people groaned under the consequent anarchy. Weary of
these commotions, the Arabs of Spain at last came to an understanding
among themselves for the election of a caliph, and their choice fell
upon one of the last survivors of the Omayyads, Abdarrahman b. Moawiya,
grandson of the caliph Hisham. This prince was wandering in the deserts
of Africa, pursued by his implacable enemies, but everywhere protected
and concealed by the desert tribes, who pitied his misfortunes and
respected his illustrious origin. A deputation from Spain sought him out
in Africa and offered him the Caliphate, which he accepted with joy. On
the 1st Rabia I. 138 (14th August 755) Abdarrahman landed in the Iberian
peninsula, where he was universally welcomed, and speedily founded at
Cordova the Western Omayyad Caliphate (see SPAIN: _History_).

While Mansur was thus losing Africa and Spain, he was trying to redeem
the losses the empire had sustained on the northern frontier by the
Byzantines. In 750-751 the emperor Constantine V. (Copronymus) had
unsuccessfully blockaded Malatia; but five years later he took it by
force and razed its wall to the ground. Mansur now sent in 757 an army
of 70,000 men under the command of his cousin Abdalwahhab, the son of
Ibrahim the Imam, whom he had made governor of Mesopotamia, the real
chief being Hasan b. Qahtaba. They rebuilt all that the emperor had
destroyed, and made this key of Asia Minor stronger than ever before.
The Moslems then made a raid by the pass of Hadath (Adata) and invaded
the land of the Byzantines. Two aunts of the caliph took part in this
expedition, having made a vow that if the dominion of the Omayyads were
ended they would wage war in the path of God. Constantine advanced with
a numerous army, but was afraid of attacking the invaders. The Moslems
also rebuilt Mopsuestia. But from 758 till 763 Mansur was so occupied
with his own affairs that he could not think of further raids.

In 758 (others say in 753 or 754) a body of 600 sectaries, called
Rawendis (q.v.), went to Hashimiya, the residence of the caliph, not far
from Kufa. They believed that the caliph was their lord, to whom they
owed their daily bread, and came to pay him divine honours. They began
by marching in solemn proce