From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 1157

Courtesy of

ʿUbaydī: Jalāl al‐Dīn Fal Allāh al‐ʿUbaydī

İhsan Fazlıoğlu


There is little information about the identity and life of ʿUbaydī. According to a recorded note in one of his works, he was the student of Qub al‐Dīn al‐Shīrāzī (Istanbul, Süleymaniye, Nuri Efendi MS 149/2, 16b–81b). Since copies of his astronomical works are extant in Turkish manuscript libraries, it is assumed that he was educated, and that he studied in Anatolia.

ʿUbaydī's work represents a continuation of the tradition of studying mathematics and astronomy at the Marāgha School and Marāgha Observatory as well as ideas put forth by Ibn al‐Haytham. He was particularly interested in ʿilm al‐hayʾa (theoretical astronomy) and wrote a commentary on Mamūd al‐Jaghmīnī's al‐Mulakhkhaʿilm al‐hayʾa al‐basīa. ʿUbaydī informs us in the preface that he wrote the commentary in 3 days at the request of some professors and students. There are at least 20 extant copies of the commentary in Turkish manuscript libraries.

ʿUbaydī wrote another important astronomical work, in February 1328, entitled Bayān al‐Tadhkira wa‐tibyān al‐tabira, which was a commentary on Naīr al‐Dīn al‐ūsī's al‐Tadhkira fī ʿilm al‐hayʾa. “Al‐tabira” in the title refers to Muammad al‐Kharaqī's al‐Tabira fī ʿilm al‐hayʾa. There are at least four extant copies of this work in Turkey.

One often finds copies of both works bound together; this was probably intentional since their contents complement one another. ʿUbaydī's two commentaries need to be examined more closely; only then will their place within the tradition of ʿilm al‐hayʾa be established. We do know, however, that ʿUbaydī's teaching of the subject in various schools certainly contributed toward making the tradition more widespread.

Selected References

Brockelmann, Carl (1943). Geschichte der arabischen Litteratur. 2nd ed. Vol. 1, p. 624. Leiden: E. J. Brill.

İzgi, Cevat (1997). Osmanlı Medreselerinde İlim. 2 Vols. Vol. 1, pp. 389, 401–402. Istanbul: iz Yayinlare.

Karatay, Fehmi Edhem (1966). Topkapı Sarayı Müzesi Kütüphanesi Arapça Yazmalar Kataloğu. Vol. 3, p. 755 (no. 7058), pp. 763–764 (no. 7083). Istanbul: TopKapi sarayi Muzesi Yayinlare.

Kātib Čelebī (1943). Kashf al‐unūn ʿan asāmī al‐kutub wa‐ʾl‐funūn. Vol. 2, col. 1819. Istanbul: Mulli Egition Bahantigi Yayinlare.

Ragep, F. J. (1993). Naṣīr al‐Dīn al‐Ṭūsī's Memoir on Astronomy (al‐Tadhkira fī ʿilm al‐hayʾa). 2 Vols. Vol. 1, pp. 61–62. New York: Springer Verlag.