Ulugh Beg

Key Accomplishments

• Built the Samarkand Observatory, housing the largest astronomical sextant of the medieval world
• Produced the "Zij-i Sultani," the most accurate star catalog before the telescope, with over 1,000 stars
• Calculated the sidereal year with precision not surpassed for over a century
• Transformed Samarkand into one of the foremost centers of scientific learning

The Full Story

Mirza Muhammad Taraghay bin Shahrukh, known as Ulugh Beg ("Great Ruler"), was born in 1394 CE in Sultaniyya, Iran. He was the grandson of the great conqueror Timur (Tamerlane) and was raised in an environment that valued both martial prowess and intellectual achievement. From 1409, he governed Samarkand and the region of Transoxiana, turning the city into one of the foremost centers of learning in the Islamic world.

Ulugh Beg's greatest achievement was the construction of his observatory in Samarkand, completed around 1420. The centerpiece was a massive sextant with a radius of approximately 36 meters, built into a trench carved from the hillside, making it the largest astronomical instrument of its kind. Working with a team of eminent astronomers including Qadi Zada al-Rumi and Jamshid al-Kashi, he produced the "Zij-i Sultani" (Sultanic Astronomical Tables), completed around 1437.

The Zij-i Sultani contained the positions of 1,018 stars measured to a degree of accuracy not surpassed until Tycho Brahe's observations over 150 years later. His measurements of the sidereal year (365 days, 5 hours, 49 minutes, and 15 seconds) were remarkably precise. He also calculated the length of the year, the obliquity of the ecliptic, and the latitude of Samarkand with extraordinary accuracy.

Tragically, Ulugh Beg's devotion to science made him politically vulnerable. In 1449, he was overthrown and executed by his own son, Abd al-Latif, reportedly with the encouragement of conservative religious factions opposed to his astronomical pursuits. His observatory was destroyed, but his star catalog survived, translated into Persian, Arabic, and eventually Latin, becoming a standard reference in both the Islamic world and Europe.

Notable Words

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Connected Figures

Sources

• [1]Kevin Krisciunas, "The Legacy of Ulugh Beg," in Astronomical Heritage of the Middle East (Springer, 2019)
• [2]E.S. Kennedy, "A Survey of Islamic Astronomical Tables," Transactions of the American Philosophical Society, 1956
• [3]Thomas Hockey et al., "The Biographical Encyclopedia of Astronomers" (Springer, 2007)