1394-1449

Central Asian ruler, astronomer, and mathematician who, in addition to gathering a number of leading scientific minds around him, made important contributions to trigonometry. A grandson of the Mongol conqueror Tamerlane, Ulugh Beg ruled the city of Samarqand, where he established a school that included Qadi Zada, al-Kashi, and others. His achievements included producing tables for sines and tangents that were correct to eight decimal places and helping to create the Zij-i sultani, a star catalogue regarded as a standard work until the seventeenth century. Little interested in ruling, Ulugh Beg was later usurped by his son, who had him put to death.