Flourished:  Toledo (Spain), eleventh century. Known for his work on “universal instruments.” Treatise on the use of the lámina universal (universal plate) preserved only in a Spanish translation included in the Libros del Saber de Astronomía (III, 11–132), compiled by the Spanish King Alfonso X. To our knowledge, the Arabic original is lost. Credited with the construction of a universal instrument called al-asṭurlāb al-ma’mūnī  in the year 1071, dedicated to al-Ma’mūn, ruler of Toledo. Mentioned in Ṣā`id al-Andalusī's Ṭabaqāt as an outstanding geometer,  belonging, along with Zarqālī, to a group of young Toledan scholars interested in philosophy. There are several variants of his name. (1) `Alī b. Khalaf b. Aḥmar Akhīr (or Akhiyar) al-Ṣaydalānī [fn in Bū `Alwān’s ed. of the Ṭabaqāt]; (2) Abū al-Ḥasan `Alī b. Khalaf b. Akhir (or Akhyar),  bearing the title al-Shajjārī, the botanist [anonymous Egyptian 14th century source in Leiden, MS 468]. So D. A. King identifes him with Abū al-Shajjār, mentioned in Zarqālī’s treatise on the ṣafīḥa zarqāliyya (MS Escorial 962). King also identifies him with `Alī al-Shajjār, who is listed in the zīj of Ibn Isḥāq (13 c.; Hyderabad Andhra Pradesh MS 298). [R. Puig]