Ulugh Beg, born in 1394 as Mīrzā Muhammad Tāraghay, governed the Timurid Empire while transforming Samarkand into a global center for mathematics and observational astronomy. Unlike his royal predecessors, his authority relied on the construction of specialized institutes and the precision of star charts, fundamentally advancing the study of spherical geometry and trigonometry in the fifteenth century.
Governance and Patronage
The grandson of the conqueror Timur, Ulugh Beg was appointed governor of Samarkand in 1409 at the age of sixteen. By 1411, he became the sovereign ruler of Mavarannahr. During his tenure, he prioritized the development of intellectual infrastructure, most notably commissioning the Ulugh Beg Madrasah between 1417 and 1420. These institutions turned Samarkand and Bukhara into primary cultural hubs of Central Asia, attracting scholars such as Jamshid al-Kashi, Qadi Zada al-Rumi, and the astronomer Ali Qushchi.
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Ulugh Beg constructed the Ulugh Beg Observatory between 1424 and 1429, which served as the largest facility of its kind in Central Asia. Lacking telescopes, he relied on a massive masonry instrument known as the Fakhri sextant, which possessed a radius of approximately 36 meters. This design allowed for high-resolution measurement of star transit altitudes. His analytical work corrected numerous errors found in the data inherited from Ptolemy.
The Zij-i-Sultani and Scientific Legacy
In 1437, he compiled the Zij-i-Sultani, a star catalogue recording the positions of 1,018 stars. This collection remains a landmark in astronomical history, surpassing previous tables in accuracy. He determined the length of the sidereal year to be 365 days, 6 hours, 10 minutes, and 8 seconds, demonstrating an error of only 58 seconds. Additionally, he calculated the tropical year at 365 days, 5 hours, 49 minutes, and 15 seconds.
Political Decline and Death
Despite his scientific achievements, Ulugh Beg struggled to maintain control over the Timurid Empire. His tenure as Timurid sultan from 1447 to 1449 was marked by failing authority and internal conflict. Opponents exploited his lack of administrative focus, leading to his eventual removal from power. He was assassinated by his son, Abd al Latif, in 1449. He was buried at the Gur-e Amir in Samarkand.
Fast facts
- Born: 1394, Soltaniyeh
- Died: 1449, Samarkand
- Positions held: Timurid sultan (1447-1449)
- Languages known: Persian, Turkic, Chagatai
- Major work: Zij-i-Sultani (1437)
- Primary burial site: Gur-e Amir
- Instrument: Fakhri sextant
Questions readers ask
What languages did Ulugh Beg speak?
Historical analysis suggests he spoke five languages: Arabic, Persian, Chaghatai Turkic, Mongolian, and a small amount of Chinese.
What was the significance of the Fakhri sextant?
The sextant was a 36-meter radius instrument used at the Samarkand observatory to increase optical accuracy when measuring the transit altitudes of stars.
Achievements
- Built the great Samarkand observatory (1424–1429), including the giant Fakhri sextant
- Compiled the Zij-i-Sultani (1437), the most accurate star catalogue of its era, listing over 1,000 stars
- Calculated the length of the sidereal year to within about a minute of the modern value
- Produced trigonometric sine and tangent tables of exceptional precision
- Has a lunar crater named in his honour
