Medieval Christians imagined even pagan astrologers prophesying Christian triumph

Evidence

Dearest son, over a hundred years ago it was discovered in our pages, and in all books of the pagans, that the Christian nation would be over us and would everywhere defeat us, and reign over pagans, and our nation would everywhere be subject to them; but I did not know if it is to be now or rather in the future. And I, sorrowing, did not desist from following you to Aleppo, that beautiful city, where, pointing and acutely investigating, I looked at the stars in the sky, and sagaciously deliberating and with sedulous mind observing the planets, and the twelve signs of the zodiac, and innumerable lots, in all these things I saw that the Christian nation would be victorious everywhere. — John V. Tolan, Saracens, 638