The ZījMu tabarSanjarī its Position and Importance in the History of Islamic Period Astronomy

In the middle Priodof Islamic astronomy, the Mu‘tabarSanjarīZīj was composed by the Iranian astronomer ‘Abd al-Rahmān al-Khāzinī (fl.475-525 A.H./1082-1130 A.D) who lived in Marw. In his introductin to his zīj he remarks that made observations for 35 years to prepare it, and he lists his innovations, especially in the field of lunar crescent visibility and in the theory of eclipse, then he demonstrates its superiority over pervious zījes in general.In this paper I present a summery of some important sections of thiszīj, and I mention the extant mss.thereof. Of course each section will need a separate through study. Despaite its importance, the Sanjarīzīj has scarcely been considered in detail by modern science historians, and its whole text has not been published yet.