Ali ibn Yunus

Abu'l-Hasan 'Ali b. Abi Sa'id 'Abd al-Rahman b. Ahmad b. Yunus b. 'Abd al-A'la al-Sadafi, the Egyptian astronomer; author of the Zij al-Hakimi known as the Zij of Ibn Yunus — a great zij that Ibn Khallikan saw in four volumes, in which the computation and its working were set down with unsurpassed exactness, the longest of all zijes he had seen; al-'Aziz of Egypt commissioned it and began it for him. ¹

He specialised in the science of the stars, commanding in all the sciences, excellent in poetry; of his absent-mindedness it is told that al-Hakim said: he came in to me one day with his sandal in his hand, kissed the ground, sat down — and left the sandal beside him. ¹