1. Abu’l-Abbas inaugurated his Caliphate by a harangue in which he announced the era of concord and happiness which was to begin now that the House of the Prophet had been restored to its right. He asserted that the Abbasids were the real heirs of the Prophet, as the descendants of his oldest uncle Abbas. Addressing the Kufians, he said, “Inhabitants of Kufa, ye are those whose affection towards us has ever been constant and true; ye have never changed your mind, nor swerved from it, notwithstanding all the pressure of the unjust upon you. At last our time has come, and God has brought you the new era. Ye are the happiest of men through us, and the dearest to us. I increase your pensions with 100 dirhems; make now your preparations, for I am the lavish shedder of blood[27] and the avenger of blood.”
Notwithstanding these fine words, Abu’l-Abbas did not trust the Kufians. He resided outside the town with the Khorasanian troops, and with them went first to Hira, then to Hāshimīya, which he caused to be built in the neighbourhood of Anbar. For their real sympathies, he knew, were with the house of Ali, and Abu Salama their leader, who had reluctantly taken the oath of allegiance, did not conceal his disappointment. Abu Jahm, the vizier (q.v.; also [Mahommedan Institutions]), or “helper,” of Abu Moslim, advised that Abu Ja‘far, the caliph’s brother, should be sent to Khorasan to consult Abu Moslim. The result was that Abu Salama was assassinated, and at the same time Suleimān b. Kathīr, who had been the head of the propaganda in Khorasan, and had also expected that the Mahdi would belong to the house of Ali. It is said that Abu Ja‘far, whilst in Khorasan, was so impressed by the unlimited power of Abu Moslim, and saw so clearly that, though he called his brother and himself his masters, he considered them as his creatures, that he vowed his death at the first opportunity.
The ruin of the Omayyad empire and the rise of the new dynasty did not take place without mighty convulsions. In Bathanīya and the Ḥaurān, in the north of Syria, in Mesopotamia and Irak Khorasan insurrections had to be put down with fire and sword. The new caliph then distributed the provinces among the principal members of his family and his generals. To his brother Abu Ja‘far he gave Mesopotamia, Azerbaijan and Armenia; to his uncle Abdallah b. Ali, Syria; to his uncle Da’ud, Hejaz, Yemen and Yamāma (Yemama); to his cousin ‘Īsā b. Mūsā, the province of Kufa. Another uncle, Suleimān b. Ali, received the government of Baṣra with Bahrein and Oman; Ismā ‘īl b. Ali that of Ahwāz; Abu Moslim, Khorasan and Transoxiana; Mahommed b. Ash‘ath, Fārs; Abu ‘Aun, Egypt. In Sind the Omayyad governor, Manṣūr b. Jomhūr, had succeeded in maintaining himself, but was defeated by an army sent against him under Mūsā b. Ka‘b, and the black standard of the Abbasids was raised over the city of Manṣūra. Africa and Spain are omitted from this catalogue, because the Abbasids never gained any real footing in Spain, while Africa remained, at least in the first years, in only nominal subjection to the new dynasty. In 754 Abu Moslim came to Irak to visit Abu’l-Abbas and to ask his permission to make the pilgrimage to Mecca. He was received with great honour, but the caliph said that he was sorry not to be able to give him the leadership of the pilgrimage, which he had already purposely entrusted to his brother, Abu Ja‘far.
Abu’l-Abbas died on the 13th of Dhu‘l-ḥijja 136 (5th June 754). He seems to have been a man of limited capacity, and had very little share in the achievements accomplished in his name. He initiated practically nothing without the consent of Abu Jahm, who was thus the real ruler. In the few cases where he had to decide, he acted under the influence of his brother Abu Ja‘far.
2. Reign of Mansur.—Abu‘l-Abbas had designated as his successors first Abu Ja‘far, surnamed al-Manṣūr (the victorious), and after him his cousin ‘Īsā b. Mūsā. Abu Ja‘far was, according to the historians, older than Abu‘l-Abbas, but while the mother of the latter belonged to the powerful Yemenite tribe of al-Ḥārith b. Ka‘b, the mother of Abu Ja‘far was a Berber slave-girl. But he was a son of Mahommed b. Ali, and was therefore preferred by Abu Moslim to his uncles and cousins. Abu‘l-Abbas, however, had promised the succession to his uncle Abdallah b. Ali, when he marched against Merwan. When the news of the death of Abu‘l-Abbas reached Abdallah, who at the head of a numerous army was on the point of renewing the Byzantine war, he came to Harran, furious at his exclusion, and proclaimed himself caliph. Abu Moslim marched against him, and the two armies met at Nisibis, where, after a number of skirmishes, a decisive engagement took place (28th November 754). Abdallah was defeated and escaped to Baṣra, where he found a refuge with his brother Suleimān. A year later he asked for pardon, and took the oath of allegiance to Mansur. The caliph spared his life for a time, but he did not forget. In 764 Abdallah met his death by the collapse of his house, which had been deliberately undermined.
The first care of Mansur was now to get rid of the powerful Abu Moslim, who had thus by another brilliant service strengthened his great reputation. On pretence of conferring with him on important business of state, Mansur induced him, in spite of the warnings of his best general, Abu Naṣr, to come to Madāin (Ctesiphon), and in the most perfidious manner caused him to be murdered by his guards. Thus miserably perished the real founder of the Abbasid dynasty, the Ṣāḥib addaula, as he is commonly called, the Amīn (trustee) of the House of the Prophet. A witty man, being asked his opinion about Abu Ja‘far (Mansur) and Abu Moslim, said, alluding to the Koran 21, verse 22, “if there were two Gods, the universe would be ruined.” The Khorasanian chiefs were bribed into submission, and order was at last re-established by Mansur’s general Khāzim b. Khozaima in Mesopotamia, and by Abu Dā’ūd, the governor of Khorasan in the east.
About the same time Africa[28] and Spain escaped from the dominion of the eastern Caliphate; the former for a season, the latter permanently. The cause of the revolt of Africa was as follows. Mansur had written to Abdarrahmān, announcing the death of Abu‘l-Abbas, and requiring him to take the oath of allegiance. Abdarrahmān sent in his adhesion, together with a few presents of little value. The caliph replied by a threatening letter which angered Abdarrahmān. He called the people together at the hour of prayer, publicly cursed Mansur from the pulpit and declared him deposed. He next caused a circular letter, commanding all Maghribins to refuse obedience to the caliph, to be read from the pulpit throughout the whole extent of the Maghrib (western North Africa). A brother of Abdarrahmān, Ilyās, saw in this revolt an opportunity of obtaining the government of Africa for himself. Seconded by many of the inhabitants of Kairawan, who had remained faithful to the cause of the Abbasids, he attacked his brother, slew him, and proclaimed himself governor in his stead. This revolution in favour of the Abbasids was, however, not of long duration. Ḥabīb, the eldest son of Abdarrahmān, who had fled in the night of his father’s murder, was captured, but the vessel which was to convey him to Spain having been detained by stress of weather, his partisans took arms and rescued him. Ilyās was marching against them, when the idea occurred to Ḥabīb of challenging him to single combat. Ilyās hesitated, but his own soldiers compelled him to accept the challenge. He measured arms with Ḥabīb, and was slain. The party of independence thus triumphed, but in the year 144 (761) Mahommed b. Ash‘ath, the Abbasid general, entered Kairawan and regained possession of Africa in the name of the eastern caliph. From the year 800, it must be added, Africa only nominally belonged to the Abbasids; for, under the reign of Harun al-Rashid, Ibrahīm b. al-Aghlab, who was invested with the government of Africa, founded in that province a distinct dynasty, that of the Aghlabites.
At the same time as the revolt in Africa, the independent Caliphate of the western Omayyads was founded in Spain. The long dissensions which had preceded 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, Abdarrahmān b. Moawiya, grandson of the caliph Hishām. 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) Abdarrahmān 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 Abdalwahhāb, the son of Ibrāhīm the Imam, whom he had made governor of Mesopotamia, the real chief being Hasan b. Qaḥṭaba. 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 Ḥadath (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 Rāwendīs (q.v.), went to Hāshimīya, 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 procession round the palace, as if it had been the Ka‘ba. Mansur being told of it said: “I would rather they went to hell in obedience to us, than to heaven in disobedience.” But as they grew tumultuous, and he saw that this impious homage gave offence to his men, he caused the principal leaders to be seized and thrown into prison. The Rāwendīs immediately rose in revolt, broke the prison doors, rescued their chiefs, and returned to the palace. The unfortunate fanatics were hunted down and massacred to the last man, and thereby the ties that bound the Abbasids to the ultra-Shi‘ites were severed. From that time forward the Abbasid caliphs became the maintainers of orthodox Islam, just as the Omayyads had been. The name of Hāshimīya, which the reigning family still retained, was henceforward derived not from Abu Hāshim, but from Hāshim, the grandfather of Abbas, the great-grandfather of the Prophet.