We have now taken a general, though perforce an extremely curtailed and disconnected, view of the political conditions which existed during the ‘Abbásid period in most parts of the Muḥammadan Empire except Arabia and Spain. The motherland of Islam had long sunk to the level of a minor province: leaving the Holy Cities out of consideration, one might compare its inglorious destiny under the Caliphate to that of Macedonia in the empire which Alexander bequeathed to his successors, the Ptolemies and Seleucids. As regards the political history of Spain a few words will conveniently be said in a subsequent chapter, where the literature produced by Spanish Moslems will demand our attention. In the meantime we shall pass on to the characteristic literary developments of this period, which correspond more or less closely to the historical outlines. The first thing that strikes the student of mediæval Arabic literature is the fact that a very large proportion of the leading writers are non-Arabs, or at best semi-Arabs, men whose fathers or mothers were of foreign, and especially Persian, race. They wrote in Arabic, because down to about 1000 A.D. that language was the sole medium of literary expression in the Muḥammadan world, a monopoly which it retained in scientific compositions until the Mongol Invasion of the thirteenth century. I have already referred to the question whether such men as Bashshár b. Burd, Abú Nuwás, Ibn Qutayba, Ṭabarí, Ghazálí, and hundreds of others should be included in a literary history of the Arabs, and have given reasons, which I need not repeat in this place, for considering their admission to be not only desirable but fully justified on logical grounds.[507] The absurdity of treating them as Persians--and there is no alternative, if they are not to be reckoned as Arabs--appears to me self-evident. "It is strange," says Ibn Khaldún, "that most of the learned among the Moslems who have excelled in the religious or intellectual sciences are non-Arabs (_‘Ajam_) with rare exceptions; and even those savants who claimed Arabian descent spoke a foreign language, grew up in foreign lands, and studied under foreign masters, notwithstanding that the community to which they belonged was Arabian and the author of its religion an Arab." The historian proceeds to explain the cause of this singular circumstance in an interesting passage which may be summarised as follows:-- [Sidenote: Ibn Khaldún's explanation of the fact that learning was chiefly cultivated by the Persian Moslems.]