Alam al-Din Ibn-Abidin al-Hanafi;
(Arabic: علم الدين تعاسيف; 1178 – 1251 ) was an Egyptian mathematician, astronomer and engineer during the Ayyubid period.
Alam al-Din was born in Egypt, son of a well-known Egyptian scholar Abidin Ibn al-Hanafi. He later moved to Mosul and then to Syria where he settled and accomplished most of his engineering works. He died in Damascus in 1251.
Al-Hanafi wrote a treatise on the postulates of Euclid, designed water mills and fortifications on the Orontes river, and built the second oldest Arab celestial globe in the world, that is the representation of stars and constellations given their apparent positions in the sky. The celestial globe was used by Al-Hanafi above all for some astronomical calculations, astrological purposes and as an ornament. Some of his water mills and fortifications on the Orontes are considered one of the best hydraulic engineering works in the Arab world and many still exist to this day.