Muhammad Taraghāy ibn Shāhrukh ibn Tīmūr better known as Ulugh Beg (Sultāniyya (Iran) on 22 March 1394 and died near Samarqand (Uzbekistan) on 27 October 1449) was a Timurid ruler as well as an astronomer, mathematician. Ulūgh Beg was the grandson of the Asian conqueror Timur (Tamerlane). His primary interest was in the sciences and intellectual matters. Under his brief rule the Timurid dynasty reached its cultural peak. His father, Shāh Rokh, captured the city of Samarkand and gave it to Ulūgh Beg, who made it a centre of Muslim culture. There he wrote poetry and history and studied the Qur'ān. His greatest interest was astronomy, and he built an observatory (begun in 1428) at Samarkand. In his observations he discovered a number of errors in the computations of the 2nd-century Alexandrian astronomer Ptolemy, whose figures were still being used.