Ibn Sīnā [Latin: Avicenna], renowned for his great works in philosophy and medicine, was also interested in the mathematical sciences; he dealt with a number of problems related to astronomy and cosmology that had an impact on later astronomical work in Islamic regions and in Europe. Ibn Sīnā left an autobiography that was completed by Abū ʿUbayd al-Jūzjānī. Ibn Sīnā lived in Bukhārā (985 -1005) where he studied Ptolemy’s Almagest, basically being self-taught. It is said that he had access to the library of Nūḥ b. Manṣūr (d. 997), which included many books by the “Ancients.” Ibn Sīnā lived in Gurganj (1005-12) where he wrote the Station of the Earth. He then resided in Jurjān (1012–14), and wrote his Comprehensive Observations, a treatise on the Correction of the Longitude of Jurjān, and his Summary of the Almagest (which he probably later incorporated into al-Shifāʾ). It was here that Jūzjānī began studying the Almagest with him. In 1014–15, Ibn Sīnā moved to Rayy and then on to Hamadhān (1015–24), where he wrote several parts of the Shifāʾ. He lived his final years in Iṣfahān, where he completed the final parts of the Shifāʾ, including the Almagest, composed the Najāt (the abridgement of the Shifāʾ that included logic, natural philosophy, and theology), and wrote his treatise on Astronomical Instruments during periods of observation for the ruler ʿAlāʾ al-Dawla. After Ibn Sīnā’s death, Jūzjānī added supplemental treatises on astronomy and mathematics to his Najāt.There are many astronomical works associated with Ibn Sīnā, but 9 can be identified as authentic, and these can be classified into four general categories: summaries of Ptolemy’s Almagest, works on instruments and observational astronomy, philosophical and cosmological works, and miscellaneous works. [BEA [S. Ragep]; for more details see Ragep and Ragep 2004]. Also see:GAL I, 589-99; Suppl. 812-828.