580 MOHAMMEDANISM [ ABBASIDS. of his followers, his body remained in the hands of the enemy. The partisans of All then dispersed, and never again ventured to have recourse to arms. The Caliph was highly delighted when he heard of the decisive victory gained by Usa, but, far from rewarding his valiant cousin, he tried to compel him to renounce his right of succession to the Caliphate, with the view of substituting as heir-presumptive his own son Mohammed. Isa at first energetically refused to abandon his rights ; but Mansur did not hesitate at a shameless ^deception, and produced false witnesses, who swore that Isa had waived his claim in favour of Mohammed b. Mansur. However unwillingly, Isa was obliged to yield his priority to Mohammed, but it was understood that, in case of the death of the latter, the succession should return to Isa. One of the false witnesses was, it is asserted, Khalid b. Barmak, the head of that celebrated Persian family the Barmecides, which played so important a part in the reign of Harun al-Rashid. To this Khdlid, Mansur had entrusted the elevated post of minister of finance. In A.H. 158 (A.D. 774-775), Mansur, feeling the decline of his powers, resolved to undertake for the last time the pilgrimage to Mecca. At the last station on the route he had a fall from his horse, and died at the gate of the Holy City. He was nearly seventy years of age, and had reigned for twenty-two years. He was buried at Mecca. Mahdi. 3. Mohammed b. Mansur was at Baghdad when he received the news of his father s death, and hastened to have himself proclaimed Caliph. He then took the title of Mahdl ("the well-directed "). To make his accession welcome to his subjects, he began by granting an amnesty to a great number of persons who had incurred the anger of Mansur, and had been thrown into prison. Among these was a certain Dawud b. Ya kub, whom Mahdi after wards made his prime minister. But, on the other hand, Mahdl did not choose to confirm in their posts the pro vincial governors in whom his father had placed confidence ; he supplied their places by creatures of his own. These changes displeased the people of Khorasan, who revolted under the leadership of a certain Yusuf b. Ibrahim, sur- named Al-Barm. Mahdi sent against him his general Yazid b. Mazyad, who, after a desperate struggle, defeated Yusuf, took him prisoner, and brought him in triumph to Baghdad, where he was put to the torture and crucified. Mahdi had been scarcely a year on the throne, when he resolved to accomplish the pilgrimage to Mecca, and at the same time to visit the tomb of his father. Leaving his eldest son Musa as governor of Baghdad, he set off, accompanied by his second son Harun and a numerous suite. The chroniclers relate that the Caliph had ordered a great number of camels to be laden with snow, and that he reached Mecca without having exhausted this store. Immediately on his arrival in the Holy City, he applied himself, at the request of the inhabitants, to the renewal of the veils which covered the exterior walls of the Ka ba. For a very long time these veils had been placed one over another, no care having been taken to remove the old covering when a new one was put on ; so that the accumu lated weight caused uneasiness respecting the stability of the walls. Mahdi caused the temple to be entirely stripped, and covered the walls again with a single veil of great richness. On this occasion he distributed considerable largesses among the Meccans. From Mecca, Mahdi went to Medina, where he caused the mosque to be enlarged. During his stay in that city he formed himself a guard of honour, composed of five hundred descendants of the Ansar, 1 to whom he assigned lands in Irak to be held in 1 The first citizens of Medina who embraced Islam were called Au.sar ; see above, p. 554. fief. Struck by the difficulties of every kind which had to be encountered by poor pilgrims who desired to repair to Mecca from Baghdad and its neighbourhood, he resolved to come to their help. His first care was to have the road from Baghdad to Mecca laid out, and its divisions marked by milestones. He next ordered the construction at every stage of a kind of inn, where the poorer travellers might find shelter and food. He also saw to having new wells dug and cisterns built along the whole route. Whilst he was devoting himself to these pious labours, he was menaced by a dangerous revolt in Khorasan. Its leader was a sectary called Hakim, surnamed Al-Mokanna or the Veiled One, because he never appeared in public without having his face covered with a mask. Al- Mokanna hoped to gather a great number of adherents around him, and to govern the province as absolutely as Abu Moslim had formerly done. His religious teaching consisted in the assertion that God had several times become incarnate among men, and that his last incarna tion was Mokanna himself. Many Persians were seduced by his words, and still more by the hope of plundering the property of the Moslems, which Mokanna promised to give up to them. The governor of Khorasan and several other generals who marched against these sectaries were defeated ; but at last the Caliph charged a skilful captain, Sa id al-Harashi, with the direction of operations, and Sa id, having compelled the impostor to throw him self into the city of Kash, soon reduced him to a choice between surrender and death. Mokanna preferred the latter alternative, and took poison. These disturbances did not suffice to turn Mahdi s thoughts from the hereditary enemy of the Caliphate. Every summer he sent expeditions into Asia Minor against the Greeks; but these were not successful, and the Caliph decided on leading his army in person. Having levied in Khorasan a large number of those mountaineers who had always distinguished themselves by their valour, he assembled his army in the plains of Baradan, on the banks of the Tigris, and commenced his march A.H. 163, taking with him his second son Harun, and leaving his eldest son Musa as governor of Baghdad. The latter was also designated as his successor in the Caliphate, f sa b. Musa having definitively renounced the throne. Mahdi traversed Mesopotamia and Syria, entered Cilicia, and established himself on the banks of the Jaihan (Pyramus). Thence he despatched an expeditionary force, at the head of which his son Harun was nominally placed. In reality, that prince being too young to direct military operations, the chief command was exercised by his tutor, the Barmecide Yahya b. Khdlid. Harun took the fortress of Sam&lu after a siege of thirty-eight days. In consequence of this feat of arms, Mahdi made Harun governor of Azerbaijan and Armenia. Two years later war broke out afresh between the Moslems and the Greeks. Leo IV., Emperor of Constantinople, had recently died, leaving the crown to Constantine Porphyrogenitus. This prince was then only ten years old, and would have been incap able of governing. His mother Irene took the regency on herself. By her orders an army of 90,000 men, under the command of Michael Lachonodracon, entered Asia Minor. The Moslems, on their side, invaded Cilicia under the orders of Abd al-Kabir, but were defeated by the Greeks. Mahdi then recalled his son Harun, and enjoined on him to avenge the failure of the arms of Islam. Harun assembled an army of nearly 100,000 men, and conceived the project of carrying the war to the very gates of Constantinople. The patrician Nicetas, who sought to oppose his march, was defeated by Hdrun s general, Yazid b. Mazyad, and forced to take refuge at
Nicomedia. Harun marched through Asia Minor, and