Ibn al‐Ha'im al‐Ishbili

Who is Ibn al‐Ha'im al‐Ishbili?

Abu Muhammad Abd al-Haqq al‐Ghafiqi al‐Ishbili, known as Ibn al‐Hāʾim was a Muslim astronomer and mathematician from Seville in Al-Andalus. He began his studies as a mathematician and studied the works of Al-Jayyani and Jabir ibn Aflah. He was the author of the al‐Zīj al‐kāmil fī al‐talim.

He gives historical data on the life and works of Al-Zarqali and the creation of the Tables of Toledo by astronomers in Toledo patronized by Said Al-Andalusi. He further extends Al-Zarqali's theories on the oscillation of the obliquity of the ecliptic, also presents the spherical trigonometrical formulae, gives a longitude of the solar apogee of 85° 49′ and further confirmed the works of Al-Zarqali. His work seems exceptional in Western Islam, as very complete and accurate, and had a great influence on the development of astronomy in the Maghreb.