Ulugh Beg Madrasa is a madrasah built by Ulugh Beg, the 4th sultan of the Timurid Empire, in Registan Square in Samarkand between 1417 and 1420. He also had an Observatory built next to the Ulugh Beg Madrasa. Ulugh Beg Madrasa was the best and most important university in Ana Asia in the 15th century.