Died 1350

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 Quṭb 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 Maḥmūd al‐Jaghmīnī'sal‐Mulakhkhaṣ fīʿilm al‐hayʾa al‐basīṭa. 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‐tabṣira, which was a commentary on Naṣīr al‐Dīn al‐Ṭūsī's al‐Tadhkira fīʿilm al‐hayʾa. “Al‐tabṣira” in the title refers to Muḥammad al‐Kharaqī'sal‐Tabṣira fīʿilm 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.