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.

[6] He also built the Ulugh Beg Madrasah (1417–1420) in Samarkand and Bukhara, transforming the cities into cultural centers of learning in Central Asia.

[8] He was a grandson of the great conqueror and king, Timur (Tamerlane) (1336–1405), and the oldest son of Shah Rukh, both of whom came from the Turkicized Mongol Barlas tribe of Transoxiana (now Uzbekistan).

[9] His mother was a noblewoman named Gawhar Shad, daughter of a member of the representative Turkic[10][11] tribal aristocracy, Ghiyasuddin Tarkhan.

Between 1417 and 1420, he built a madrasa ("university" or "institute") on Registan Square in Samarkand (currently in Uzbekistan), and he invited numerous Islamic astronomers and mathematicians to study there.

Qadi Zada al-Rumi was the most notable teacher at Ulugh Beg's madrasa and Jamshid al-Kashi, an astronomer, later came to join the staff.

Ulugh Beg utilized dimensions from al-Sufi and based his star catalogue on a new analysis that was autonomous from the data used by Ptolemy.

[14] Throughout his life as an astronomer, Ulugh Beg came to realize that there were multiple mistakes in the work and subsequent data of Ptolemy that had been in use for many years.

This catalogue, one of the most original of the Middle Ages, was first edited by Thomas Hyde at Oxford in 1665 under the title Jadāvil-i Mavāzi' S̱avābit, sive, Tabulae Long.

Ulugh Beg also determined the Earth's axial tilt as 23°30'17" in the sexagesimal system of degrees, minutes and seconds of arc, which in decimal notation converts to 23.5047°.

[17] In mathematics, Ulugh Beg wrote accurate trigonometric tables of sine and tangent values correct to at least eight decimal places.

[19] In 1416, Ming envoys Chen Cheng and Lu An presented silk and silver stuffs to Ulugh Beg on behalf of the Yongle emperor.

[20] Ulugh Beg's emissaries came across Ghiyāth al-dīn Naqqāsh and other envoys representing Shah Rukh, Prince Baysunghur, and other Timurid authorities in Beijing; however, they stayed at separate hostelries.

Here, he heard that Ala al-Dawla, the son of his late brother Baysunghur, had claimed the rulership of the Timurid Empire in Herat.

[24][25][26] Eventually, Ulugh Beg's reputation was rehabilitated by his nephew, Abdallah Mirza (1450–1451), who placed his remains at Timur's feet in the Gur-e-Amir in Samarkand,[27] where they were found by Soviet archaeologists in 1941.