with Abyssinia may be placed as far back as the lifetime of Prince Henry (_c._ 1450). The Christianity of Nubia, which dated from the fourth century like that of Abyssinia itself, was still vigorous in the twelfth,[92] but from that time it began to fail before the incessant and determined pressure of Islam. Ibn-Batuta,[93] about 1330-40, found that the King of Dongola had just become a Moslem. Father Alvarez, in 1520-7, considered that the Nubian Christianity which had once extended up the Nile from the first Cataract to Sennaar had become extinct; though he would not allow that the mass of the Nubians had adopted any other religion in its place;[94] and himself, he tells us, had met a Christian who, in travelling through Nubia, had seen 150 churches.[95] But, in the course of the sixteenth and seventeenth centuries, all Nubia embraced Islam; and even in 1534, Ahmad Gragne, King of Adel, in one of his attacks upon Abyssinia, is said to have had 15,000 Nubian allies, apparently all Mohammedans.[96] [Footnote 92: Edrisi, Climate I, section iv; vol. i, p. 35 (Jaubert). See Duchesne, _Eglises Séparées_.] [Footnote 93: _Ibn-Batuta_, iv, 396. (Defrémery and Sanguinetti).] [Footnote 94: See _Alvarez_, Hakl. Soc. Edition, p. 352.] [Footnote 95: Ruins?] [Footnote 96: See Nerazzini, _Musulman Conquest of Ethiopia_, Rome 1891. (Ital. Transl. from Arab MS.).] In Prince Henry's day, then, we may fairly assume that the old Christianity of East Africa was practically limited to Abyssinia; but when Azurara tells us of the Infant's desire "to know if there were in those parts[97] any Christian Princes,"[98] and again more explicitly, "to have knowledge of the land of Prester John,"[99] it is possible that some dim acquaintance with the old tradition of an isolated African (as well as of an isolated Asiatic) Church, was at the root of his endeavour. [Footnote 97: Africa.] [Footnote 98: _Azurara_, c. vii.] [Footnote 99: _Ibid._, c. xvii.] At the end of the twelfth century, Islam had already begun to encroach upon the coast of what is now Italian "Erythraea;" and about 1300 A.D. a Musulman army attacked the ruler of Amhara. At this time the realm of the Negus seems to have been completely cut off from the Red Sea;[100] but it was not till the early sixteenth century that Abyssinia was in serious danger of becoming a province of Islam, from the attacks of Ahmad Gragne (1528-1543), which, however, ended in complete failure. [Footnote 100: See Maqrīzī, _Histoire des Sultans Mamlouks de l'Egypte_, Quatremère, 1837-45, t. ii, Pt. 11, p. 183.]