Muslih al-Din Mustafa ibn Ali al-Qustantini al-Rumi[1] was born in Istanbul, the capital of the Ottoman Empire, in the early sixteenth century.

[1][3] This decision was made in order to popularise the field of astronomy in the Ottoman state, to make it accessible to more students, and to facilitate the mention of non-Arabic place names.

According to the historian of science İhsan Fazlıoğlu, the relatively high number of extant copies of his works was an indication of the success of his attempt to reach a wider audience by using Turkish.

[4] Among his earliest works was a book of mathematical geography titled I'lam al-'ibad fi a'lam al-bilad ("Notices on the Distances of Cities of the World"), written in Ottoman Turkish.

Among these, Faraḥ Fazā was dedicated to the grand vizier Pargalı Ibrahim Pasha and describes the horizontal quadrant (al-rub' al-afaqi), which according to Mustafa was his own invention.

His other works, Kifayat al-waqt, also known as Risala fi al-muqantarat (1529), was written in Turkish and describes an instrument called the astrolabic quadrant, as well as other themes in geometry, trigonometry, and astronomy.

[1] After Mustafa's death, Sultan Selim II appointed the prominent scholar Taqi ad-Din Muhammad ibn Ma'ruf—who just returned to Istanbul in 1570 after his service in the Egypt Eyalet—as his successor.