Ulugh Beg
Mīrzā Muhammad Tāraghay entered the world on the 22nd of March 1394 within the city of Sultaniyeh. His birth occurred during a massive military campaign led by his grandfather Timur, also known as Tamerlane. The great conqueror had invaded Persia when Ulugh Beg was born into the Turkicized Mongol Barlas tribe. He grew up wandering across substantial parts of the Middle East and India while his family expanded their conquests in those regions. After Timur died in 1405, Shah Rukh moved the empire's capital to Herat in modern Afghanistan. Sixteen-year-old Ulugh Beg became governor of Samarkand in 1409. In 1411 he assumed sovereign rule over all of Mavarannahr. His mother Gawhar Shad came from a noble tribal aristocracy through her father Ghiyasuddin Tarkhan.
The young ruler set out to transform Samarkand into an intellectual center for the entire empire. Between 1417 and 1420 he constructed a madrasa university on Registan Square in Samarkand. This building still survives today in Uzbekistan. Ulugh Beg invited numerous Islamic astronomers and mathematicians to study at this institution. Ali Qushchi emerged as his most famous pupil in astronomy before dying in 1474. Qadi Zada al-Rumi served as the most notable teacher at the madrasa. Jamshid al-Kashi later joined the staff as another prominent astronomer. The madrasa transformed both Samarkand and Bukhara into cultural centers of learning across Central Asia. These institutions laid the foundation for what scholars would later call the Timurid Renaissance.
Astronomy piqued Ulugh Beg's interest when he visited the Maragheh Observatory at a young age. Nasir al-Din al-Tusi practiced there during earlier centuries. In 1428 Ulugh Beg built an enormous observatory similar to Tycho Brahe's later Uraniborg. Lacking telescopes to work with, he increased accuracy by extending the length of his sextant. The so-called Fakhri sextant had a radius that allowed optical separability of 180 seconds of arc. This instrument measured transit altitudes of stars above the horizon. It could only measure the declination of celestial objects. The observatory became the largest in Central Asia and one of the finest in the Islamic world. With these instruments Ulugh Beg composed a star catalogue containing 1018 stars. He compiled the 1437 Zij-i-Sultani featuring 994 stars generally considered the greatest between Ptolemy and Tycho Brahe.
In mathematics Ulugh Beg wrote accurate trigonometric tables of sine and tangent values correct to at least eight decimal places. Using a 50 meter high gnomon over many years he determined the sidereal year as 365 days 6 hours 10 minutes 8 seconds. This measurement carried an error of plus 58 seconds compared to modern values. Nicolaus Copernicus improved this value by 28 seconds in 1525. Ulugh Beg later measured another more precise value for the tropical year as 365 days 5 hours 49 minutes 15 seconds with an error of plus 25 seconds. This proved more accurate than Copernicus's estimate which had an error of plus 30 seconds. He also determined Earth's axial tilt as 23 degrees 30 minutes 17 seconds converting to 23.5047 degrees in decimal notation. These calculations demonstrated remarkable precision for the fifteenth century without optical telescopes.
Once Ulugh Beg became governor of Samarqand he fostered diplomatic relations with the Yongle emperor of the Ming dynasty. In 1416 Ming envoys Chen Cheng and Lu An presented silk and silver stuffs to Ulugh Beg on behalf of the emperor. The Timurid sent their own emissaries Sultan-Shah and Muhammad Bakhshi to the Ming court in 1419. Ghiyāth al-dīn Naqqāsh even saw the Yongle emperor riding a black horse with white feet gifted by Ulugh Beg. In 1439 the Zhengtong emperor ordered an artist to produce a painting of that same black horse with white feet and a white forehead. Six years later the Ming emperor sent a letter expressing gratitude for all tribute from Samarqand. The emperor sent vessels made of gold and jade along with a spear featuring a dragon's head. Fine horses with saddles and variegated gold-embroidered silk stuffs were also exchanged between the courts.
Ulugh Beg led two major campaigns against his neighbors beginning in 1425 against Moghulistan and its ruler Shir Muhammad. He was victorious but the impact remained limited as Shir Muhammad stayed in power. A year later Baraq Khan of the Golden Horde laid claim to Timurid possessions around the Syr Darya including Sighnaq. In 1427 Ulugh Beg marched against Baraq accompanied by his brother Muhummad Juki. The Timurid army was surprised by a smaller enemy force on a hill close to Sighnaq and soundly defeated. This humiliation had lasting effects since it became his last campaign against neighboring powers. His armies would not win resounding victories afterward while territories faced raids from northern and easterly foes. In 1439 he defeated his nephew Ala al-Dawla at Murghab before advancing toward Herat where he massacred people. Abul-Qasim Babur Mirza then defeated Ulugh Beg allowing him to retreat to Balkh.
Abd-al-Latif released his father from custody after forcing surrender but ensured Ulugh Beg never reached Mecca. He assassinated both Ulugh Beg and his brother Abdal-Aziz in 1449. Eventually Ulugh Beg's reputation was rehabilitated by his nephew Abdallah Mirza between 1450 and 1451. Abdallah placed his remains at Timur's feet in the Gur-e-Amir in Samarkand where they were found by Soviet archaeologists in 1941. The crater Ulugh Beigh on the Moon was named after him by Johann Heinrich von Mädler on his 1830 map. Main-belt asteroid 2439 Ulugbek discovered on the 21st of August 1977 by N. Chernykh bears his name. The dinosaur Ulughbegsaurus received its name in 2021 honoring the astronomer. Soviet anthropologist Mikhail M. Gerasimov reconstructed the face showing close resemblance to Mongoloid type with slightly Europoid features.
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Common questions
When and where was Ulugh Beg born?
Mīrzā Muhammad Tāraghay entered the world on the 22nd of March 1394 within the city of Sultaniyeh. His birth occurred during a massive military campaign led by his grandfather Timur, also known as Tamerlane.
What major astronomical instruments did Ulugh Beg construct in Samarkand?
In 1428 Ulugh Beg built an enormous observatory similar to Tycho Brahe's later Uraniborg that included the Fakhri sextant with a radius allowing optical separability of 180 seconds of arc. This instrument measured transit altitudes of stars above the horizon and could only measure the declination of celestial objects.
How accurate were Ulugh Beg's measurements of the sidereal year compared to modern values?
Using a 50 meter high gnomon over many years he determined the sidereal year as 365 days 6 hours 10 minutes 8 seconds which carried an error of plus 58 seconds compared to modern values. Nicolaus Copernicus improved this value by 28 seconds in 1525.
Who were the notable astronomers who studied at Ulugh Beg's madrasa university?
Ali Qushchi emerged as his most famous pupil in astronomy before dying in 1474 while Qadi Zada al-Rumi served as the most notable teacher at the institution. Jamshid al-Kashi later joined the staff as another prominent astronomer.
What diplomatic exchanges occurred between Ulugh Beg and the Ming dynasty?
In 1416 Ming envoys Chen Cheng and Lu An presented silk and silver stuffs to Ulugh Beg on behalf of the emperor. The Timurid sent their own emissaries Sultan-Shah and Muhammad Bakhshi to the Ming court in 1419 and exchanged fine horses with saddles and variegated gold-embroidered silk stuffs.