Kushy Ā r Ibn Labb Ā n B Ā shahr Ī , Abu- ’ l- Ḥ asan, Al-J Ī l Ī

( fl . Ca . 1000)

astronomy, trignometry, arithmetic .

Little known about Kushy ā r ’ s life. The word “ al-J ī l ī ” added to his name refers to J ī l ī n, a region of northern Iran south of the Caspian Sea.

The earliest arabic biographers to write about Kushy ā r is al-Bayhaq ī ( d . 1065), who states that Kushy ā r lived in Baghdad and died about A. H. 350 (A. D. 961). Later biographers copy al-Bayhaq ī and add several attributes to Kushy ā r name, including the title “ al-kiya, ” which seems to mean “ master. ...