Ulugh Beg

He was the grandson of the conqueror Timur the Lame (1336-1405) and son of Shah Rukh[?], both of whom were of the Turkic Barlas tribe of Transoxania (present Uzbekistan). Ulugh Beg was born in Sultaniyya in modern-day Iran. As a child he wandered through a substantial chunk of the Middle East and India as his grandfather expanded his conquests in those areas. With Timur's death, however, and the accession of Ulugh's father to much of the Timurid Empire[?], he settled in Samarkand which had been Timur's capital. After Shah Rukh moved the capital to Herat (in modern Afghanistan), sixteen year-old Ulugh Beg was made the shah's governor in Samarkand in 1409. In 1411 he became a sovereign of the whole Mavarannhar[?] khanate[?].

The teenaged ruler set out to turn the city into an intellectual center for the empire. In 1417-1420 he built a madrasa[?] ("university" or "institute") on Rigestan Square[?] in Samarkand, and invited numerous Islamic astronomers and mathematicians to study there. Ulugh Beg's most famous pupil in mathematics was Ghiyath al-Kashi[?].

His own particular interest was in astronomy, and in 1428 he built an enormous observatory, similar to Tycho Brahe's later Uranienborg. Lacking telescopes to work with, he increased his accuracy by increasing the length of his sextant; the so-called Fakhri Sextant[?] had a radius of circa 36 meters and the optical separability[?] of 180". Using it he compiled the 1437 Zij-i Sultani[?] of 994 stars, generally considered the greatest of star catalogues between those of Ptolemy and Brahe. The same year he determined the length of the sidereal year of 365^d 6^h 10^m 8^s (an error +58^s). This value was improved by 28^s in 1525 by Nicolaus Copernicus, who appealed to the estimation of Thabit ibn Qurra, which was accurate to +2^s. Ulugh Beg was also notable for his work in astronomy-related mathematics, such as trigonometry and spherical geometry.

Unfortunately for Ulug he was the heir of Shah Rukh, and when his father died in 1447 he became ruler of the Timurid Empire[?]. Within two years he was beheaded by his own son, Abd al-Latif[?], while on his way to Mecca. Eventually, however, he was rehabilitated by his grandson Babur, founder of the Mogul Empire, who placed Ulugh Beg's remains in the tomb of Timur in Samarkand. There they were found by archeologists in 1941.

In honour of his achievements, a crater on the Moon has been named for him, Ulug Beigh (the spelling used by the German astronomer Johann Heinrich von Mädler[?] (1794-1874) who proposed the name in his 1830 map of the Moon).