One of the most accomplished and prolific scientists at the Samarqand Observatory. He was also a physician (mentioned at the end of his Risāla dar sharḥ-i ālāt-i raṣd). Born in Kāshān (northern Iran), in his Zīj he states that he had lived in poverty in various cities of central Iran. He found patronage in Herat at the court of Shāh Rukh (son of Tīmūr; father of Ulugh Beg). On June 2, 1406 Kāshī witnessed an eclipse of the Moon in Kāshān, as he did also in 1407 as well as in 1416 at which time he presented his book the Nuzha. Presumably between 1417 and 1419 he was invited to Samarqand by Ulugh Beg where he joined the scientific circle (most likely in 1420). He eventually became the prince’s closest collaborator and consultant; in the introduction of Ulugh Beg’s Zīj, Kāshī is singled out for praise. When the observatory was founded in 1420, Kāshī took part in its construction, organization, and provision, as well as in the preparation of Ulugh Beg’s Zīj. During this time, he traveled with the royal retinue to Bukhārā. [P. Schmidl] 