Ulugh Beg's star catalogue. Page from an edition of 'Zij-i Sultani', an astronomical table and star catalogue published in 1437 by the Timurid astronomer Ulugh Beg (1394-1449). Ulugh Beg took his observations at Samarkand, in what is now Uzbekistan. The Timurids were a Central Asian people of Turko-Mongol descent and Persian culture. This star catalogue was one of the most extensive and accurate of the medieval period. Later editions were printed in 1665, 1767, 1843 and 1917.