Ulugh Beg was notable for his work in astronomy-related mathematics, such as trigonometry and spherical geometry, as well as his general interests in the arts and intellectual activities. It is thought that he spoke five languages: Arabic, Persian, Turkic, Mongolian, and a small amount of Chinese. During his rule (first as a governor, then outright) the Timurid Empire achieved its cultural peak through Ulugh Beg's attention and patronage. Samarkand, which was captured and given to Ulugh Beg by his father Shah Rukh, became the headquarters of Muslim culture.
He built the great Ulugh Beg Observatory in Samarkand between 1424 and 1429. It was considered by scholars to have been one of the finest observatories in the Islamic world at the time and the largest in Central Asia. Ulugh Beg was subsequently recognized as the most important observational astronomer from the 15th century by many scholars. He also built the Ulugh Beg Madrasah (1417–1420) in Samarkand and Bukhara, transforming the cities into cultural centers of learning in Central Asia.
However, Ulugh Beg's scientific expertise was not matched by his skills in governance. During his short reign, he failed to establish his power and authority. As a result, other rulers, including his family, took advantage of his lack of control and he was subsequently overthrown and assassinated.