Abbas,
who resided at Homaima in the south-east of Syria, obtained the secrets
of the party and took the lead (A.H. 98, see above). This Mahommed, the
father of the two first Abbasid caliphs, was a man of unusual ability
and great ambition. He directed his energies primarily to Khorasan. The
missionaries were charged with the task of undermining the authority of
the Omayyads, by drawing attention to all the injustices that took place
under their reign, and to all the luxury and wantonness of the court, as
contrasted with the misery of many of their subjects. God would not
suffer it any longer. As soon as the time was ripe that time could not
be far off--He would send a saviour--and out of the house of the
Prophet, the Mahdi, who would restore Islam to its original purity. All
who desired to co-operate in this holy purpose must pledge themselves to
unlimited obedience to the Imam, and place their lives and property at
his disposal. As a proof of their sincerity they were required at once
to pay a fixed sum for the Imam. The missionaries had great success,
especially among the non-Arabic inhabitants of Khorasan and Transoxiana.

Mahommed b. Ali died A.H. 126 (A.D. 743-744), and his son Ibrahim, the
Imam, took his place. Ibrahim had a confidant about whose antecedents
one fact alone seems certain, that he was a _maula_ (client) of Persian
origin. This man, Abu Moslim by name, was a man of real ability and
devoted to his master's cause. To him, in 745-746, the management of
affairs in Khorasan was entrusted, with instructions to consult in all
weighty matters the head of the mission, the Arab Suleiman b. Kathir. At
first the chiefs of the mission were by no means prepared to recognize
Abu Moslim as the plenipotentiary of the heir of the Prophet. In the
year 129 he judged that the time for open manifestation had arrived. His
partisans were ordered to assemble from all sides on a fixed day at
Siqadenj in the province of Merv. Then, on the 1st Shawwal (15th June
747), the first solemn meeting took place and the black flags were
unfolded. On that occasion Suleiman b. Kathir was still leader, but by
the end of the year Abu Moslim, whom the majority believed to belong
himself to the family of the Prophet, was the acknowledged head of a
strong army. Meantime, Nasr had moved from Nishapur to Merv, and here
the two Arabic armies confronted each other. Then, at last, the true
significance of Abu Moslim's work was recognized. Nasr war