# Ulugh Beg: the astronomer-king

> Timur's grandson who ruled Samarkand 1411–1449 and built a 40-metre observatory that measured the year accurate to 25 seconds — unmatched until Tycho Brahe 150 years later.

**Mirza Muhammad Taraghay** (1394–1449), known by his title **Ulugh Beg** ("Great Ruler"), was Timur's grandson through Shah Rukh. He governed Samarkand from 1411 and became sole ruler of Transoxiana in 1447.

Unlike his grandfather, Ulugh Beg was a scholar first and a warrior second. His achievements:

- Built the **Ulugh Beg Observatory** (1424–1428) on Kuhak hill, with a 40-metre Fakhri sextant.
- Produced the **Zij-i Sultani** (1437) — a star catalogue of 1,018 stars and planetary tables that were the most accurate in the world until Tycho Brahe's work in the 1570s.
- Calculated the tropical year at 365 days, 5 hours, 49 minutes, 15 seconds — within 25 seconds of the modern value.
- Built the **Ulugh Beg Madrasa** at the Registan (1417–1420) with astronomical motifs on the portal.
- Attracted scholars from across the Islamic world: **Qadi-zada al-Rumi** (Turkish mathematician), **Jamshid al-Kashi** (Persian calculator of pi to 16 digits), **Ali Qushji** (who later brought Timurid science to the Ottoman court).

His end was brutal: in 1449 his own son Abdullatif had him assassinated during a pilgrimage trip. The observatory was subsequently destroyed by religious conservatives. Ulugh Beg was buried at Gur-e-Amir beside his grandfather Timur.

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Keywords: Ulugh Beg, astronomy, observatory, Samarkand, Timurid, science
Updated: 2026-08-15
Category: history
URL: https://uzbguidedtours.com/kb/kb-history-ulugh-beg-astronomy