Al-Ashraf Umar II

al‐Malik al‐Ashraf (Mumahhid al‐Dīn) ʿUmar ibn Yūsuf ibn ʿUmar ibn ʿAlī ibn Rasūl (born c. 1242, died 22 November 1296 in Yemen) was the third Rasulid sultan and a polymath. He is known for writing the first description of the use of a magnetic compass for determining the qibla. Also, his works on astronomy contain important information on earlier sources.

In a treatise about astrolabes and sundials, al-Ashraf includes several paragraphs on the construction of a compass bowl (ṭāsa). He then uses the compass to determine the north point, the meridian (khaṭṭ niṣf al-nahār), and the Qibla towards Mecca. This is the first mention of a compass in a medieval Islamic scientific text and its earliest known use as a Qibla indicator, although al-Ashraf did not claim to be the first to use it for this purpose.