Abu Abdallah Ibn Zaydan al-Tilimsani

Ibn Zaydan was an illustrious astronomer, geometrician, and instrument maker who served as chief timekeeper ('muwaqqit') of the Great Mosque of Tlemcen during the Zayyanid golden age. Living in the 14th century, he designed sophisticated brass astrolabes, quadrants, and universal sundials calibrated to the latitude of Tlemcen.

His treatises on spherical trigonometry, the determination of the qibla azimuth, and the calculation of planetary conjunctions were widely studied across the universities of North Africa and Fez. His precision instruments exemplified the sophisticated scientific culture of medieval Tlemcen.