As soon as the Khalif Abu l-`Abbas was seated on the throne his chief aim was to secure the establishment of his dynasty by getting rid of all possible rivals, and it was the vigour he showed in doing this which earned for him the title of “the Butcher.” First of all he hunted down and slew all the representatives he could find of the `Umayyad family. One of these escaped, `Abdu r-Rahman, and went to Africa where he endeavoured to form a body of supporters without success, and then crossed over to Spain where in 138 he established himself at Cordova, and there he and his descendants ruled until 422 A.H. These Spanish `Umayyads claimed to be legitimist rulers, but never assumed the divine claims of the `Alid section. Abu Muslim, who had done most to establish the `Umayyad dynasty, next provoked the Khalif’s jealousy, probably with good cause for he was indignant to find that “the Butcher” was no sooner on the throne than he entirely discarded the Shi`ites who had helped to place him there, and so within the first year of the `Abbasid rule Abu Muslim was put to death. The fall of the `Umayyads brought an end to the tyranny of the Arab minority, as it now was, and placed the preponderance for a clear century (A.H. 132-232) in Persian hands. The government was remodelled on Persian lines, and to Persian influence was due the institution of the _wazir_ or responsible minister at the head of the executive. The title is probably identical with the Old Persian _vi-chir_ or “overseer” (thus Darmesteter: _Etudes Iraniennes_ i. p. 58. note 3.); before this the chief minister was simply clerk (_kàtib_) or adviser (_mushir_) and was simply one of the Khalif’s attendants who was employed to conduct correspondence, or to give advice when occasion required. In 135 the noble Persian family of Barmecides began to supply _wazirs_, and these controlled the policy of the Khalifate until 189. From the time of al-Mansur (A.H. 136-158) onwards the Persians began to assert their pre-eminence and a party was formed known as the _Shu`ubiyya_ or “anti-Arab party” of those who held, not only that the alien converts were equal to the Arabs, but that the Arabs were a half savage and inferior race in all respects, contrasting unfavourably with the Persians, Syrians, and Copts. This party produced considerable mass of controversial literature in which free course was given to the general dislike felt towards the Arabs and which reveals the intensity of the contempt and hatred felt towards these parvenus. The Arabs had boasted of their racial descent and had devoted much attention to the keeping of their genealogies, at least in the century immediately preceding the rise of Islam; as they had then only just commenced to count descent in the father’s line these genealogies were purely fictitious in so far as they dealt with pre-Islamic ancestors. The Arabs were in fact a parvenu people only just emerging out of barbarism (cf. Lammens: _Le berceau de l’islam._ p. 117). But the